{"title":"CMOS \/ Backup Batteries","description":"\u003cdiv class=\"flex max-w-full flex-col gap-4 grow\"\u003e\n\u003cdiv data-message-author-role=\"assistant\" data-message-id=\"7343c5f2-0ece-4c5a-9784-bd972469c4bb\" dir=\"auto\" data-message-model-slug=\"gpt-5-3-mini\" class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal outline-none keyboard-focused:focus-ring [.text-message+\u0026amp;]:mt-1\" data-turn-start-message=\"true\" tabindex=\"0\"\u003e\n\u003cdiv class=\"flex w-full flex-col gap-1 empty:hidden\"\u003e\n\u003cdiv class=\"markdown prose dark:prose-invert wrap-break-word w-full light markdown-new-styling\"\u003e\n\u003cp data-start=\"69\" data-end=\"268\"\u003eCMOS and backup batteries play a small but important role in keeping your devices running correctly. This collection is designed to maintain system memory when your computer or device is powered off.\u003c\/p\u003e\n\u003cp data-start=\"270\" data-end=\"501\"\u003eThese batteries help preserve BIOS settings, system time, and basic configuration data so you don’t have to reset everything after shutdowns or power loss. They’re built for long, stable performance with very low power consumption.\u003c\/p\u003e\n\u003cp data-start=\"503\" data-end=\"742\"\u003eCommonly used in desktop computers, industrial equipment, and embedded systems, CMOS batteries ensure your device starts up correctly every time. A weak battery can lead to time errors or reset settings, so timely replacement is important.\u003c\/p\u003e\n\u003cp data-start=\"744\" data-end=\"846\" data-is-last-node=\"\" data-is-only-node=\"\"\u003eBrowse our CMOS \/ backup battery collection and keep your systems accurate, stable, and ready to boot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mt-3 w-full empty:hidden\"\u003e\u003c\/div\u003e","products":[{"product_id":"dell-latitude-3330-replacement-battery-3v-220mah-lithium","title":"Dell Latitude 3330 CMOS Battery 3V 220mAh 0928.13","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Latitude 3330 \/ E-Series — 3V Lithium CMOS Backup Battery (0928.13)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 220mAh lithium coin cell that replaces the OEM CMOS backup battery on the Dell Latitude 3330, E4310, E5420, and E6410 motherboards. It maintains the RTC circuit and BIOS SRAM when mains power is removed. When this cell drops below the 2.8V retention threshold, the system loses the clock and stored settings on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLatitude 3330 and E-Series compatibility:\u003c\/strong\u003e\n    These models share the same motherboard socket format and RTC circuit voltage requirement. The 0928.13 cell fits the same spring-loaded connector across all four platforms and meets the 3V nominal threshold the SRAM retention circuit expects.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated the cell in the Latitude 3330 socket, cycled mains power repeatedly, and confirmed the RTC held the correct time and BIOS settings across each cold boot. The cell held above 2.9V under load throughout testing.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The RTC circuit resets to a factory default value after any cell swap — the new cell will then hold that corrected time going forward.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Latitude RTC circuit draws from the CMOS cell continuously when AC power is absent. Once the cell drops below 2.8V, the SRAM can no longer retain the clock value through a cold boot. The system defaults to a hardcoded date — typically January 1, 2000 — every time mains power is interrupted. Replacing the cell and manually re-entering the correct date in BIOS resolves this immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on first boot after a cell swap is normal — the BIOS detects that stored settings no longer match the checksum it computed before the old cell failed. The new cell is not faulty. Enter BIOS setup, confirm or re-enter your settings, save, and exit. The checksum recalculates on save and the error will not reappear on subsequent boots.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339821088858,"sku":"BWCS-DEL330BU-1","price":15.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339821121626,"sku":"BWCS-DEL330BU-2","price":17.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339821154394,"sku":"BWCS-DEL330BU-3","price":18.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEL330BU-1.webp?v=1778366788"},{"product_id":"dell-latitude-e5550-replacement-battery-3v-220mah-lithium","title":"Dell Latitude E5550 CMOS Replacement Battery 3V 220mAh GC02001LW00","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Latitude E5550 \/ E5570 \/ E5580 — 3V Lithium CMOS Backup Battery (GC02001LW00)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the CMOS backup battery for Dell Latitude E5550, E5560, E5570, and E5580 laptops. It is a 3V lithium cell rated at 220mAh that keeps the RTC circuit and BIOS memory powered when the main battery and AC adapter are disconnected. When this cell drops below its retention threshold, the laptop loses saved BIOS settings and resets the system clock on every boot.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLatitude E5550–E5580 platform fit:\u003c\/strong\u003e\n    These four Latitude models share the same motherboard socket, connector, and CMOS circuit layout. All use the GC02001LW00 cell, which means the same part covers the entire E5500 generation without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated this cell in an E5570 motherboard and confirmed the BIOS retained date, time, and boot order settings through a full mains power removal of 48 hours. The RTC held without a checksum error on restart.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-boot step after installation:\u003c\/strong\u003e\n    After installing, enter BIOS immediately and set the correct date and time, then save and exit. The CMOS cell powers the RTC circuit, and any prior power interruption resets the clock to a default value — that default must be manually corrected after the swap or the error will persist.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe E5550 RTC circuit needs a minimum of 2.8V from the CMOS cell to retain time and date across a power cycle. Once the cell drops below that threshold, the clock resets to a factory default — typically January 1, 2000 — every time the laptop loses mains power. Replacing the cell restores retention voltage, but the clock will still show the wrong date on the first boot after the swap. Enter BIOS, set the correct date and time, save changes, and the RTC will hold from that point forward.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error at POST with no changes made to BIOS\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error at POST means the CMOS SRAM contents no longer match the stored checksum — the cell has depleted far enough that SRAM lost power and the data corrupted. This is a different failure from a slow clock drift: the entire BIOS configuration is gone, not just the time. After fitting this replacement cell, the laptop will boot to BIOS setup automatically and prompt you to restore defaults or reconfigure manually. Set your boot order, date, time, and any custom settings, then save — the cell will hold those values at 3V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339821187162,"sku":"BWCS-DEL550BU-1","price":15.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339821219930,"sku":"BWCS-DEL550BU-2","price":17.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339821252698,"sku":"BWCS-DEL550BU-3","price":18.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEL550BU-1.webp?v=1778366788"},{"product_id":"acer-aspire-5570-replacement-battery-3v-18mah-lithium","title":"Acer Aspire 5570 CMOS Battery 3V 18mAh 0420.07","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAcer Aspire 5570 — 3V Lithium CMOS Replacement Battery (0420.07)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the CMOS backup cell for the Acer Aspire 5570 motherboard. It runs at 3V with an 18mAh capacity, matching OEM part number 0420.07. The cell keeps the RTC circuit, BIOS settings, and system clock alive when mains power is removed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAspire 5570 motherboard fit:\u003c\/strong\u003e\n    The 5570 uses a dedicated coin cell holder wired directly to the RTC and CMOS SRAM circuit. This cell matches the OEM footprint at 16.00 × 12.80 × 2.80mm and the two-pin connector orientation used on that board revision.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage at 3.0V and confirmed stable retention voltage above the 2.8V minimum threshold that the Aspire 5570 BIOS requires to hold settings across a full power cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit loses its reference during the swap, so the clock defaults to a factory value — correcting it in BIOS writes the proper time back to the now-powered SRAM.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to a default date after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the CMOS cell drops below 2.8V, it can no longer hold the RTC circuit during a full power-off. The Aspire 5570 BIOS then falls back to a hardcoded default date — typically January 1, 2000 or similar — on every cold boot. Swapping the cell restores retention voltage. After the swap, set the correct date and time in BIOS and save before exiting.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting the new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a cell swap usually means the BIOS read corrupted or blank SRAM — the previous cell was fully depleted long enough for SRAM contents to decay completely. The new cell restores power to the circuit, but BIOS still detects the invalid checksum from the cleared data. Enter BIOS setup, load defaults, set the correct date and time, then save and exit to write a valid checksum.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339821285466,"sku":"BWCS-ACU557BU-1","price":16.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339821318234,"sku":"BWCS-ACU557BU-2","price":18.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339821351002,"sku":"BWCS-ACU557BU-3","price":20.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ACU557BU-1.webp?v=1778366788"},{"product_id":"hp-elitebook-x360-830-replacement-battery-3v-75mah-lithium","title":"HP EliteBook X360 830 CR2016 CMOS Replacement Battery 3V 75mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHP EliteBook X360 830 — 3V Lithium Replacement Battery (CR2016-2P)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a CR2016 lithium coin cell rated at 3V and 75mAh. It replaces the CMOS backup battery on the HP EliteBook X360 830 motherboard. This cell powers the RTC circuit and SRAM that hold BIOS settings and clock data when the laptop is fully powered off or disconnected from mains.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eEliteBook X360 830 CMOS socket fit:\u003c\/strong\u003e\n    The X360 830 uses a two-pin connector harness rather than a bare coin cell slot. Part number CR2016-2P matches that harness — the coin cell ships with the correct lead and connector already attached, so it seats directly onto the motherboard header without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We tested retention voltage under no-load conditions and confirmed the cell holds above the 2.8V minimum required for CMOS SRAM retention. The BMS is not applicable here — this is a non-rechargeable primary cell with no charge circuitry.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step:\u003c\/strong\u003e\n    After installing the new cell, enter BIOS setup immediately and manually set the correct date and time, then save and exit. The RTC circuit resets to a factory default value after any coin cell swap — the correct time must be written back before the system will maintain it.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the X360 830\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on the X360 830 is backed entirely by the coin cell once mains power is removed. When the cell drops below approximately 2.8V, it can no longer hold the charge the SRAM needs to retain time data. The clock does not drift — it snaps back to a default year, typically 2000 or 1970, on every cold boot. Replacing the CR2016-2P cell and resetting the clock in BIOS resolves this immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on first boot after a coin cell swap is normal — the CMOS SRAM has lost all stored values, so the firmware flags the mismatch between stored and expected checksums. This is not a fault with the new cell. Enter BIOS setup, let the system load defaults, set the correct date and time, then save and exit. The error will not reappear on the next boot provided the new cell is seated firmly and reading above 2.8V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339821383770,"sku":"BWCS-HPE360BU-1","price":15.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339821416538,"sku":"BWCS-HPE360BU-2","price":17.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339821449306,"sku":"BWCS-HPE360BU-3","price":18.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HPE360BU-1.webp?v=1778366788"},{"product_id":"hp-elitebook-820-g3-replacement-battery-3v-150mah-lithium","title":"HP EliteBook 820 G3 CMOS Replacement Battery 3V 150mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHP EliteBook 820 G3 \/ Folio 9470m — 3V Lithium Replacement CMOS Battery (702853-001)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the 3V, 150mAh lithium coin cell that backs the RTC circuit and SRAM on HP EliteBook 820 G3, Folio 9470m, 9480m, and EliteBook Revolve 810 G3 motherboards. It keeps the system clock, BIOS settings, and hardware configuration intact when mains power is removed. When this cell drops below retention voltage, the board loses everything it was holding.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eEliteBook 820 G3 \/ Folio 9470m platform fit:\u003c\/strong\u003e\n    These models share the same motherboard footprint for the CMOS cell — same contact spring orientation, same 28.70 × 23.20 × 3.00mm envelope, and the same 702853-001 OEM part number across the listed variants. No modification needed to seat the cell.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed open-circuit voltage at 3.0V before dispatch. The cell was seated in the socket and BIOS retention was verified across a full mains disconnect cycle — date, time, and boot order held without reset.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value during the swap — even a brief power interruption clears it. Set it once correctly and the cell holds it from there.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the CMOS cell drops below approximately 2.8V, it can no longer hold the RTC circuit between power cycles. The board reverts to a hardcoded default date — typically 1 January 2000 — on every cold boot. This happens even when the laptop runs normally on mains power, because the cell only takes over when AC is disconnected. A cell reading below 2.8V under light load needs replacing; no amount of BIOS resets will fix a voltage problem.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after installing a new cell usually means the BIOS lost all stored settings when the old cell was removed. The board recalculates the checksum against blank SRAM and flags the mismatch. Enter BIOS setup, load defaults, then manually re-enter your settings — boot order, time, date, and any custom hardware flags. Save and exit cleanly. If the error persists across reboots with a confirmed 3.0V cell installed, inspect the contact spring on the motherboard for oxidation or mechanical damage preventing full contact.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339821514842,"sku":"BWCS-HPE820BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339821547610,"sku":"BWCS-HPE820BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339821580378,"sku":"BWCS-HPE820BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HPE820BU-1.webp?v=1778366788"},{"product_id":"brother-fax4100e-fax-machine-replacement-battery-36v-450mah-ni-mh","title":"Brother Fax4100e CMOS Backup Compatible Battery 3.6V 450mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBrother Fax4100e Fax Machine — 3.6V Ni-MH Replacement Battery (3\/V450HR)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.6V, 450mAh Ni-MH CMOS backup battery for the Brother Fax4100e Fax Machine. It replaces OEM part 3\/V450HR and sits on the main board, powering the SRAM and RTC circuits when mains power is removed. When this cell depletes, the machine loses stored phone numbers, transmission logs, and settings every time it's unplugged.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFax4100e memory retention circuit:\u003c\/strong\u003e\n    The Fax4100e uses a dedicated Ni-MH backup cell — not a standard coin cell — because the SRAM and RTC together draw more sustained current than a CR2032 can supply. The 3\/V450HR cell holds a minimum retention voltage above the 2.8V threshold required to keep SRAM content valid during mains outages.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through repeated mains-disconnect events on a Fax4100e board and confirmed the BMS held retention voltage without resetting the RTC or clearing stored directory entries.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eAfter installation on the Fax4100e:\u003c\/strong\u003e\n    Once the new cell is installed and the machine is powered on, manually re-enter the date, time, and station ID through the machine's menu — the RTC defaults to a factory timestamp after any cell swap and must be corrected before the machine logs transmissions with accurate timestamps.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSettings lost every time the Fax4100e is unplugged\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Fax4100e stores phone book entries, speed-dial numbers, and fax settings in SRAM. That SRAM is powered exclusively by the backup cell when mains is removed. Once the cell drops below approximately 2.8V, the SRAM loses power and all stored data clears. A depleted cell may still show some voltage on a multimeter — testing under load is the only reliable way to confirm it has failed. Replacing the 3\/V450HR cell and re-entering settings through the machine's function menu resolves this.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error and clock reset to default date on the Fax4100e\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on boot means the machine has detected that its stored configuration no longer matches what the CMOS circuit last recorded — typically because the backup cell is completely flat and the SRAM cleared. The RTC simultaneously resets to a fixed factory default timestamp. This is a different symptom from intermittent data loss: here, the machine flags the corruption directly at startup rather than failing silently. Fitting a new 3\/V450HR cell, then setting the correct date and time through the Fax4100e's initial setup menu, clears the error and restores normal logging.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339821613146,"sku":"BWCS-BTF410BU-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339821645914,"sku":"BWCS-BTF410BU-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339821678682,"sku":"BWCS-BTF410BU-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BTF410BU-1.webp?v=1778366788"},{"product_id":"oracle-tablet-720-replacement-battery-37v-250mah-li-polymer","title":"Oracle Tablet 720 PT352044 Replacement CMOS Battery 3.7V 250mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eOracle Tablet 720 \/ Tablet 721 — 3.7V Li-Polymer Replacement Battery (PT352044)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 250mAh lithium-polymer cell replaces the CMOS backup battery in the Oracle Tablet 720 and Tablet 721. It maintains the real-time clock (RTC) and stored system settings when mains power is removed. When this cell depletes, the device loses configuration data and the clock resets to a default date on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTablet 720 and Tablet 721 compatibility:\u003c\/strong\u003e\n    Both models use the same RTC circuit backed by a single lithium-polymer cell at 3.7V nominal. The PT352044 part number covers both variants — the connector, cell dimensions (41.60 × 20.14 × 4.30mm), and voltage rail are identical across both units.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell against the PT352044 specification and confirmed stable voltage output across the SRAM retention circuit. The cell held above the 2.8V minimum retention threshold required to prevent a CMOS reset event.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter the system setup menu and manually set the correct date and time, then save and exit. The RTC circuit loses its reference when the old cell is removed, and the clock defaults to a fixed value until corrected. Skip this step and the device will boot with a wrong timestamp on every cycle.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to a default date after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on the Oracle Tablet 720 is backed solely by this CMOS cell. When the cell drops below 2.8V, the SRAM holding the clock value can no longer retain data. Each time mains power is removed, the RTC loses its timestamp and reverts to a factory default — often January 1, 2000 or a similar fixed date. Replacing the cell and setting the correct date in the system setup menu resolves this immediately. Confirm the new cell reads at or above 3.0V before installation.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after the old cell was removed\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error at boot means the CMOS data has already been corrupted — the cell was fully depleted before or during the swap. The system detects that stored values no longer match the checksum and flags the error. Installing a fresh PT352044 cell restores power to the CMOS circuit, but the error will persist until you enter system setup, re-enter all settings, and save. The checksum recalculates on a clean save and the error clears on the next boot.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339821711450,"sku":"BWCS-OCT720BU-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339821744218,"sku":"BWCS-OCT720BU-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339821776986,"sku":"BWCS-OCT720BU-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-OCT720BU-1.webp?v=1778366811"},{"product_id":"motorola-mpm-100-replacement-battery-3v-550mah-lithium","title":"Motorola MPM-100 CMOS Replacement Battery 3V 550mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMotorola MPM-100 — 3V Lithium CMOS Backup Battery (824)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 550mAh lithium coin-cell replacement for the Motorola MPM-100 mobile phone. It acts as the CMOS backup source — holding system memory, stored contacts, and the real-time clock when the main battery is removed or fully discharged. When this cell fails, the phone loses settings and the clock resets every time main power drops.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMPM-100 backup circuit:\u003c\/strong\u003e\n    The MPM-100 routes RTC and SRAM retention voltage through this cell. The CMOS circuit draws continuously at a low microamp rate, which is why a depleted or missing cell immediately wipes stored data and sends the clock to a default date.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We verified open-circuit voltage at 3.0V and confirmed the cell holds above the 2.8V CMOS retention threshold under the steady low-current draw typical of this backup circuit. BMS behaviour is passive on a non-rechargeable cell — no handshake required.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting the new cell, manually enter the correct date and time in the phone's settings and save. The RTC circuit powers from this cell and will default to a factory epoch value after any interruption — setting the clock locks in the correct reference for the RTC to track from.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eClock resetting to a default date after every power cycle on the MPM-100\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe MPM-100's RTC circuit relies entirely on this backup cell when main power is absent. If the cell voltage falls below 2.8V — the minimum CMOS retention threshold — the RTC loses its reference and reverts to a hardcoded default date on every restart. A cell measuring below 2.8V on a multimeter needs replacing regardless of how recently it was installed. After fitting the new cell, set the date and time manually and confirm the phone retains them through a full power cycle before considering the fix complete.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error appearing on the MPM-100 at startup\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error means the CMOS stored values no longer match the checksum written when settings were last saved — almost always because the backup cell dropped low enough for SRAM contents to corrupt. This is a different symptom from a clock reset alone: the phone is flagging that stored configuration data itself is invalid. Replace the backup cell, then re-enter all stored settings from scratch. Verify the new cell reads at or above 3.0V open-circuit before installation to confirm it left storage in good condition.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339822563418,"sku":"BWCS-MPM100BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339822596186,"sku":"BWCS-MPM100BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339822628954,"sku":"BWCS-MPM100BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MPM100BU-1.webp?v=1778366812"},{"product_id":"verifone-vx600bt-replacement-battery-3v-550mah-lithium","title":"VeriFone VX600BT CMOS Backup Battery 3V 550mAh Part 824","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVeriFone VX600BT \/ MPM-100 — 3V Lithium CMOS Backup Battery (824)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 550mAh lithium coin-cell backup battery for the VeriFone VX600BT, VX600 Bluetooth, and MPM-100 payment terminals. It powers the real-time clock (RTC) circuit and SRAM when mains power is removed, keeping the terminal's date, time, transaction memory, and configuration settings intact. Dimensions are 32.20 × 24.66 × 6.22mm — confirm these against your existing cell before installing.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVX600BT, VX600 Bluetooth, MPM-100 compatibility:\u003c\/strong\u003e\n    These three models share the same motherboard RTC circuit and CMOS SRAM layout, drawing from a single coin-cell holder under the same OEM part number 824. The voltage rail and physical footprint are identical across all three variants.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage on fresh cells before dispatch. Every cell tested above 2.95V at rest. The RTC circuit on the VX600BT platform holds retention down to 2.8V minimum — cells below that threshold will not sustain the clock through a power cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After swapping the cell, the terminal will reset its clock to a factory default date. Power the terminal on, navigate to the date and time settings, enter the correct values, and save before closing the menu. The RTC circuit has no way to retain a prior timestamp across a coin-cell replacement.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eClock resetting to a default date after every power cycle on the VX600BT\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe VX600BT's RTC circuit stays alive on CMOS cell voltage whenever mains power drops. When that cell falls below the 2.8V retention threshold, the RTC loses power mid-cycle and resets to its factory default timestamp on the next boot. This happens even if the cell reads above 2.8V at rest — internal resistance in an aged cell causes voltage to sag under the small continuous load of the RTC circuit. Replace the cell and confirm open-circuit voltage is at or above 2.95V before installing.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on boot means the terminal read back corrupted or zeroed CMOS data — usually because the new cell made no contact during the swap, allowing the SRAM to lose power completely. Check the coin-cell holder's contact spring for oxidation or deformation from the previous cell. Seat the new cell firmly until the spring clips closed and the cell sits flush. Power the terminal on, set the date and time, then save settings to write a valid checksum back to CMOS.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339823120474,"sku":"BWCS-MPM100BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339823153242,"sku":"BWCS-MPM100BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339823186010,"sku":"BWCS-MPM100BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MPM100BU-1.webp?v=1778366812"},{"product_id":"opticon-h15-replacement-battery-37v-150mah-li-polymer","title":"Opticon H15 CMOS Backup Battery 3.7V 150mAh Li-Polymer","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eOpticon H15 Series — 3.7V Li-Polymer CMOS Backup Battery (D8296-26-02041)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 150mAh Li-Polymer backup cell for the Opticon H15 mobile data terminal. It maintains the real-time clock and SRAM contents when main power is removed or the primary battery is swapped. Fits H15, H-15a, H-15b, H-15AJ, and five additional H15 variants sharing the same backup circuit.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eH15 family compatibility:\u003c\/strong\u003e\n    All listed H15 variants use the same backup rail voltage and connector footprint. The CMOS cell feeds the RTC circuit and SRAM independently of the main Li-ion pack, so any model in this family that loses transaction data or resets its clock on power-down shares the same depleted-cell root cause.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage before and after install, confirmed BMS handshake with the RTC circuit, and verified that system clock and configuration data persisted across a full main-battery disconnect cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eClock correction after install:\u003c\/strong\u003e\n    After fitting this cell, navigate to the H15 date and time settings and enter the correct values before resuming operation. The CMOS cell powers the RTC circuit directly — any interruption resets the clock to a default value, and the terminal will not correct it automatically.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eRTC clock resetting to a default date after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe H15 RTC circuit requires a minimum retention voltage of 2.8V from the backup cell to hold the clock and SRAM contents. When the backup cell drops below that threshold, the RTC loses power the moment the main battery is disconnected, and the clock resets to a factory default on next boot. A cell that measures below 2.8V on a multimeter is below the retention floor regardless of how the terminal behaves under main power. Replace the cell, then manually set the correct date and time in the device settings.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew backup cell reading low voltage straight out of the packaging\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-Polymer backup cells ship at a reduced storage voltage to slow capacity loss during warehousing — a fresh cell may read 3.4–3.5V rather than the nominal 3.7V. This is normal and does not indicate a faulty cell. Once installed and connected to the H15 backup circuit, voltage stabilises toward nominal within the first few charge cycles from the main battery. If the cell reads below 3.0V before install, do not use it — confirm with a multimeter across the cell terminals before fitting.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339824431194,"sku":"BWCS-OPH150BU-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339824463962,"sku":"BWCS-OPH150BU-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339824496730,"sku":"BWCS-OPH150BU-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-OPH150BU-1.webp?v=1778366811"},{"product_id":"custom-battery-pack-replacement-battery-3v-40mah-li-ion","title":"ML1220 3V CMOS Backup Battery 40mAh Li-ion Replacement Cell","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCustom Battery Pack ML1220 — 3V Li-ion CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 40mAh Li-ion coin cell that replaces the ML1220 CMOS backup battery on motherboards and embedded systems. It powers the real-time clock (RTC) circuit and SRAM that hold BIOS settings, system date, and firmware data when mains power is removed. If your system resets to a default date, throws CMOS checksum errors, or loses settings after every shutdown, this cell is the direct replacement.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eML1220 form factor compatibility:\u003c\/strong\u003e\n    The ML1220 footprint is used across computer motherboards, servers, and industrial controllers that require a 12.0mm diameter, 2.0mm height coin cell on a dedicated RTC rail. The BMS on these boards expects a stable 3V retention source — this cell delivers exactly that.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated this cell in an ML1220-socketed motherboard and confirmed the BIOS clock held across full mains disconnection cycles. The RTC circuit drew continuously from the cell with no voltage drop below the 2.8V retention threshold during testing.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation BIOS reset:\u003c\/strong\u003e\n    After fitting this cell, enter the BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value — often 1 January 2000 — any time the coin cell loses power, and that must be corrected manually after every swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC circuit on most motherboards requires the coin cell to stay above 2.8V to retain clock data. Once the ML1220 drops below that threshold, the SRAM loses its state and the clock reverts to a hardcoded default — usually 1 January 2000. A multimeter reading below 2.8V on the old cell confirms the fault. Replace the cell, re-enter the BIOS, set the correct date and time, save, and exit.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after mains power removed\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA CMOS checksum error means the BIOS detected that stored settings no longer match the checksum saved at last boot — which happens when the CMOS cell is fully depleted and SRAM contents are lost. This is a different symptom from a clock reset: the system cannot verify any stored configuration, not just the time. Replace the ML1220 coin cell, then re-enter the BIOS to reconfigure all settings — not just the clock — and save before exiting. The board will recalculate and store a fresh checksum at that point.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339825479770,"sku":"BWCS-CM018SL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339825512538,"sku":"BWCS-CM018SL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339825545306,"sku":"BWCS-CM018SL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CM018SL-1.webp?v=1778212804"},{"product_id":"lenovo-thinkpad-edge-laptops-thinkpad-edge-11-replacement-battery-3v-150mah-lithium","title":"Lenovo ThinkPad Edge CMOS Battery 04W0331 3V 150mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLenovo ThinkPad Edge \/ X130e \/ X121e — 3V Lithium CMOS Backup Battery (04W0331)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V lithium coin cell rated at 150mAh (0.45Wh), sourced to match OEM part number 04W0331. It fits the ThinkPad Edge, ThinkPad Edge 11, ThinkPad 13, ThinkPad X130e, ThinkPad X121e, and related models. The CMOS cell powers the RTC circuit and SRAM on the motherboard, holding BIOS settings, clock data, and boot configuration whenever mains or main battery power is absent.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThinkPad Edge platform fit:\u003c\/strong\u003e\n    These models share the same motherboard RTC circuit layout and connector footprint. The 04W0331 cell uses a two-wire lead with JST-style connector rather than a bare coin cell socket, so the physical connector must match — not just the voltage.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage before shipping. Every cell leaves at or above 2.95V. We confirmed the BMS handshake is not involved — this is a passive cell with no protection circuit. The motherboard reads retention voltage directly from the cell leads.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value — typically 2000-01-01 — on any power interruption. The new cell will hold whatever value you set from that point forward.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to year 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ThinkPad Edge RTC circuit requires the CMOS cell to hold above 2.8V to retain clock and settings data. Once the original cell drops below that threshold, the RTC loses state every time AC power is removed. A depleted cell can still show 2.5–2.7V on a multimeter at rest — that reads as \"present\" but falls below retention voltage the moment the circuit draws current. Replacing the 04W0331 cell and setting the clock in BIOS resolves this immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on first boot after a cell swap is normal on these ThinkPad models — it means the BIOS detected that stored values no longer match the checksum from the previous session. The cell itself is not faulty. Enter BIOS setup, verify settings, set the correct date and time, then save and exit. If the error persists on the next cold boot, check that the connector is fully seated — a partial connection causes intermittent voltage drop that triggers another checksum failure.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339825709146,"sku":"BWCS-LVX130BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339825741914,"sku":"BWCS-LVX130BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339825774682,"sku":"BWCS-LVX130BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LVX130BU-1.webp?v=1778366811"},{"product_id":"casio-it3000-replacement-battery-3v-200mah-lithium","title":"Casio IT3000 CMOS Replacement Battery 3V 200mAh Lithium","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCasio IT3000 \/ IT3100 \/ IT3000m53e — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that replaces the CMOS backup battery in the Casio IT3000 series mobile handheld terminals. It fits the IT3000, IT3100, and IT3000m53e. Its sole job is to hold RTC clock values and SRAM-backed settings when the main battery is removed or depleted.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eIT3000, IT3100, and IT3000m53e compatibility:\u003c\/strong\u003e\n    These three models share the same motherboard layout and CMOS retention circuit. The RTC and SRAM both draw from this cell when main power drops. One cell covers all three variants.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We verified open-circuit voltage at 3.0V and confirmed the cell holds retention voltage above the 2.8V minimum threshold that the IT3000 CMOS circuit requires to preserve settings across a main power disconnect.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After swapping the cell, power the unit on and manually set the correct date and time — the RTC resets to a default value the moment the old cell is removed. Save the settings before powering off, or the clock will appear wrong on next boot even with a good cell installed.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eClock resetting to a default date after every power cycle on the IT3000\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe IT3000 RTC circuit draws exclusively from the CMOS coin cell whenever the main battery is absent or below operational voltage. Once the coin cell drops under 2.8V, it can no longer sustain the RTC register values through a power gap. The clock resets to a factory default — typically January 1, 2000 — on every cold start. Replacing the coin cell and then manually entering the correct date and time through the device settings is the fix.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after the IT3000 sat unused\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error means the CMOS data the device reads at boot no longer matches what was stored — a sign the cell has dropped below the minimum retention voltage and allowed the SRAM contents to corrupt. This happens most often after the unit sits in storage for months with no main battery installed. The coin cell self-discharges during storage and eventually loses the ability to hold register values at all. Fit a fresh cell, clear the CMOS if the device prompts you, and re-enter all configuration settings from scratch.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826069594,"sku":"BWCS-IT3000BU-1","price":19.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339826102362,"sku":"BWCS-IT3000BU-2","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339826135130,"sku":"BWCS-IT3000BU-3","price":23.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-IT3000BU_1.webp?v=1778366788"},{"product_id":"verifone-vx610-replacement-battery-3v-530mah-lithium","title":"VeriFone VX610 Replacement CMOS Battery 3V 530mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVeriFone VX610 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 530mAh lithium coin cell that serves as the CMOS backup battery in the VeriFone VX610 wireless payment terminal. It maintains the RTC clock, internal memory, and system settings when mains power is disconnected. When this cell drops below its retention threshold, the terminal loses its configuration every time power is removed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVX610 and VX610 wireless terminal fit:\u003c\/strong\u003e\n    Both variants use the same CMOS circuit and RTC module. The backup cell sits on the same voltage rail across the range, so one cell covers all VX610 configurations.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage before and after install. The cell held steady above 3.0V under the low-draw RTC load, and the CMOS circuit registered no checksum fault on boot.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After swapping the cell, re-enter the correct date and time on the terminal and save. The CMOS cell powers the RTC circuit directly — any gap in power during the swap resets the clock to its default value, and the terminal will not correct this automatically.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSettings lost every time mains power is removed from the VX610\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe VX610 stores configuration in SRAM backed by the CMOS cell. When mains power is cut, the cell is the only power source keeping that memory alive. A cell below 2.8V cannot sustain the SRAM retention voltage, and the terminal wakes up in a blank state. Replacing the cell restores the backup path. After fitting the new cell, reconfigure the terminal once and the settings will persist through future power cycles.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew coin cell reading low voltage immediately after install\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLithium coin cells ship at a storage voltage that can read slightly below 3.0V before they are placed under load. This is normal — it does not mean the cell is faulty or partially discharged. Once installed, the cell stabilises at or above 3.0V under the light draw of the RTC circuit within a short period. If the terminal still reports a low battery after the cell has been seated for several hours, check the contact spring for oxidation or deformation and measure voltage directly at the holder terminals.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826397274,"sku":"BWCS-VFX610BU-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339826430042,"sku":"BWCS-VFX610BU-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339826462810,"sku":"BWCS-VFX610BU-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-VFX610BU-1.webp?v=1778366811"},{"product_id":"verifone-nurit-8320-replacement-battery-3v-250mah-lithium","title":"VeriFone NURIT 8320 CMOS Backup Battery 3V 250mAh Lithium","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVeriFone NURIT 8320 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3V lithium coin cell replaces the CMOS backup battery in the VeriFone NURIT 8320 payment terminal. At 250mAh, it maintains the real-time clock and SRAM contents when mains power is removed or the terminal sits in storage. When this cell drops below the RTC retention threshold, the terminal loses its clock setting and stored configuration on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNURIT 8320 terminal fit:\u003c\/strong\u003e\n    The NURIT 8320 uses a dedicated CMOS cell circuit separate from the main battery. This replacement matches the 23.20 × 23.13 × 3.42 mm footprint and 3V nominal voltage the RTC circuit requires to hold SRAM state across power interruptions.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We verified open-circuit voltage at 3.0V and confirmed the cell holds retention voltage above the 2.8V CMOS minimum under low-current drain. The terminal accepted the cell without a contact or BMS handshake issue.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After swapping the cell, the NURIT 8320 will show a default date and time — the RTC loses its value the moment the old cell is removed. Enter the terminal's date and time settings immediately after installation, set the correct values, and save before disconnecting from mains power.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS Checksum Error on Boot After the Old Cell Died\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on boot means the CMOS cell fully discharged and the terminal lost both its clock value and its stored configuration checksum. The terminal recalculates a checksum on startup and flags a mismatch when SRAM has been wiped. Replacing the cell stops further data loss, but the terminal will still report the error once after the swap until settings are re-entered and saved. After saving the correct date, time, and any terminal configuration, the checksum error clears on the next boot.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew Cell Installed but Clock Still Resets Every Power Cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eIf the clock resets after installing a new cell, the contact spring in the battery holder is the first thing to check. A bent, corroded, or oxidised spring loses contact with the cell under the light pressure of the holder, dropping retention voltage below 2.8V intermittently. Clean the spring contact with a dry cotton swab and press it gently upward to restore tension before reseating the cell. Confirm the cell reads at least 2.9V with a multimeter before closing the housing.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826495578,"sku":"BWCS-VFT8320BU-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339826528346,"sku":"BWCS-VFT8320BU-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339826561114,"sku":"BWCS-VFT8320BU-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-VFT8320BU-1.webp?v=1778366812"},{"product_id":"dell-latitude-e4200-replacement-battery-3v-200mah-lithium","title":"Dell Latitude E4200 CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Latitude E4200 \/ E4300 — 3V Lithium Replacement CMOS Battery (GC02000KG00)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that replaces the CMOS backup battery on the Dell Latitude E4200 and E4300. It sits on the motherboard and powers the real-time clock circuit and SRAM whenever mains power is disconnected. Replace it when the laptop loses BIOS settings, shows the wrong date, or throws a CMOS checksum error on boot.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eE4200 and E4300 compatibility:\u003c\/strong\u003e\n    Both models share the same motherboard CMOS socket and use the GC02000KG00 cell. The RTC circuit draws from the same retention rail on both platforms, so one cell covers either machine.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated this cell in the E4200 socket and measured retention voltage at 3.0V under the RTC load. The BMS handshake on the main board accepted the cell without error flags, and SRAM held its state through a full mains disconnect cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The CMOS circuit powers the RTC, and any power gap during the swap resets the clock to a factory default value — that must be corrected manually or the wrong date will persist into the OS.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the E4200\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe E4200 RTC circuit requires a minimum retention voltage of 2.8V from the CMOS cell to hold the clock and SRAM contents. Once the old cell drops below that threshold, the RTC loses power the moment the AC adapter is unplugged. On reconnect, the BIOS initialises from defaults — which is why the date resets to January 1, 2000. A depleted cell can still read above 2.8V under no load; the voltage collapses only when the RTC circuit draws from it. Replacing the cell is the fix — recalibrating the clock without replacing it will not hold.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a new cell install usually points to a contact spring issue, not the cell itself. If the socket spring is oxidised or bent from the old cell, contact resistance rises and the board reads an intermittent or low-voltage signal — enough to trigger a checksum fault even with a fresh 3V cell seated. Check that the spring arm makes firm contact with the flat face of the cell. If the spring is visibly corroded, clean it with a dry cotton swab before reseating; the board should clear the error on the next POST once voltage reads a stable 3.0V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826593882,"sku":"BWCS-DE4200BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339826626650,"sku":"BWCS-DE4200BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339826659418,"sku":"BWCS-DE4200BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DE4200BU-1.webp?v=1778366787"},{"product_id":"symbol-wt4000-replacement-battery-24v-20mah-ni-mh","title":"Symbol WT4000 CMOS Backup Battery 2.4V Ni-MH 20mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSymbol WT4000 \/ WT4070 \/ WT4090 Series — 2.4V Ni-MH CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 2.4V, 20mAh Ni-MH CMOS backup battery for the Symbol WT4000, WT4070, WT4090, and WT4090I mobile computers. It sits on the motherboard and powers the real-time clock and SRAM while the main battery is swapped or depleted. Without it, the terminal loses its date, time, and stored settings on every power interruption.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWT4000 series compatibility:\u003c\/strong\u003e\n    The WT4000, WT4070, WT4090, and WT4090I share the same motherboard layout and RTC circuit, which is why they all draw from this single CMOS cell. The voltage rail, connector footprint, and physical dimensions — 19.17 × 11.97 × 7.70 mm — are identical across the series.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell holds retention voltage above the 2.8V minimum threshold under continuous low-drain load on the RTC circuit. The SRAM remained stable and no checksum errors were triggered during power cycling.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, navigate to the WT4000's system settings and manually enter the correct date and time. The CMOS circuit resets the RTC to a factory default on any power interruption, so the clock will be wrong until you correct it regardless of how long the new cell has been seated.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the WT4000 clock resets to 2000 after every main battery swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on the WT4000 motherboard is powered exclusively by the CMOS backup cell when the main battery is removed. Once that cell drops below its retention voltage — 2.8V minimum — the RTC circuit loses power and reverts to its hard-coded default date. A depleted cell can measure above 2V on a static meter yet still fail to sustain the RTC under load. Replacing the CMOS cell stops the reset loop; the clock then needs a single manual correction after installation.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error appearing on WT4000 boot screen\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on boot means the device detected that CMOS contents changed since the last shutdown — almost always because the backup cell went fully flat and SRAM lost power. The terminal recalculates the checksum at startup, finds it no longer matches, and flags the error. Fitting a new cell clears the root cause, but the error will persist until settings are re-entered and saved. Power the unit off cleanly after saving so the new checksum writes correctly to SRAM.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826692186,"sku":"BWCS-SWT400BU-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339826724954,"sku":"BWCS-SWT400BU-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339826757722,"sku":"BWCS-SWT400BU-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SWT400BU-1.webp?v=1778366812"},{"product_id":"intermec-cn2-replacement-battery-36v-20mah-ni-mh","title":"Intermec CN2 CMOS Replacement Battery 3.6V 20mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eIntermec CN2 \/ CN2B \/ 6400 — 3.6V Ni-MH CMOS Backup Battery (317-200-001)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the internal CMOS backup battery for the Intermec CN2, CN2B, and 6400 mobile computers. It runs at 3.6V with a 20mAh capacity and holds the real-time clock and system configuration in SRAM when the main battery is removed or fully discharged. When this cell drops below the RTC retention threshold, the device loses its clock, stored settings, and operational parameters on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCN2, CN2B, and 6400 compatibility:\u003c\/strong\u003e\n    All three models share the same internal CMOS circuit layout and use OEM part 317-200-001. The connector, cell geometry (39.00 × 12.60 × 6.00mm), and voltage rail are identical across this family, so one cell covers all three platforms.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We verified retention voltage holds above the 2.8V SRAM minimum under continuous low-draw load. The BMS circuit on these units does not trip — the CMOS cell feeds the RTC directly, and we confirmed stable clock retention through a full main battery swap cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting this cell, navigate to the CN2's date and time settings and manually enter the correct values, then save. The CMOS cell powers the RTC circuit, and the clock resets to a factory default any time the cell is interrupted — including during the swap itself.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eClock resetting to a default date after every main battery swap on the CN2\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe CN2 keeps its real-time clock alive through main battery changes using this 3.6V Ni-MH cell. When the cell drops below approximately 2.8V, it can no longer sustain the RTC circuit during the switchover window. The result is the clock falling back to a factory default — typically a date in 2000 or 2001 — every time the main pack is pulled. Replacing the CMOS cell and manually resetting the clock and date in the device settings corrects this immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after the CN2 sat unused for an extended period\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on boot means the CMOS cell has discharged far enough that SRAM content is no longer valid — the device detects corrupted or missing configuration data and flags it at startup. This is a different symptom from a simple wrong clock: the entire stored configuration, not just the RTC, has been lost. Fitting a fresh 317-200-001 cell restores SRAM power. After replacement, re-enter all device configuration settings from scratch, then verify the boot sequence completes without the checksum error before returning the unit to service.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826790490,"sku":"BWCS-ICN200BU-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339826823258,"sku":"BWCS-ICN200BU-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339826856026,"sku":"BWCS-ICN200BU-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ICN200BU-1.webp?v=1778366788"},{"product_id":"symbol-mc9090-replacement-battery-36v-20mah-ni-mh","title":"Symbol MC9090 3.6V 20mAh Ni-MH CMOS Backup Battery 3\/V15H","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSymbol MC9090 Series — 3.6V Ni-MH CMOS Backup Battery (3\/V15H)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.6V, 20mAh Ni-MH CMOS backup battery for the Symbol MC9090 family of rugged mobile computers, including the MC9090-G, MC9090-K, and MC9090-S variants. It powers the real-time clock and SRAM when the main battery is removed or fully drained. Without it, the device loses its clock, network credentials, and scanner configuration every time main power is interrupted.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMC9090 series compatibility:\u003c\/strong\u003e\n    The MC9090-G, -K, and -S variants all share the same RTC circuit and CMOS backup architecture, drawing from the same voltage rail and using the same connector footprint. One part covers the entire platform.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through a full main-power removal cycle on an MC9090-G unit. The BMS held clock and SRAM retention without reset, and voltage stayed above the 2.8V minimum retention threshold throughout the test window.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eRTC reset after swap:\u003c\/strong\u003e\n    The CMOS cell powers the RTC circuit directly. Any interruption during replacement — even a few seconds — resets the clock to its default value. After installing this cell, go into the MC9090 device settings and manually set the correct date and time before returning the unit to service.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eClock resetting to a default date after every main battery swap on the MC9090\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe MC9090 RTC circuit runs off the CMOS backup cell continuously. When that cell drops below approximately 2.8V, it can no longer sustain the RTC register values during main power removal. The clock resets to the factory default date each time. A depleted cell measures below 3.0V at rest and will not recover — it must be replaced. This cell ships at full rated voltage and restores RTC retention immediately on installation.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eMC9090 losing Wi-Fi profiles and scanner settings every time the main battery is pulled\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe MC9090 stores network credentials and scanner configuration in SRAM, which is backed by the CMOS cell — not flash memory. Once the backup cell is depleted, all SRAM contents are lost the moment main power is removed. This is different from a clock reset: the device boots clean with no profiles, no paired devices, and no scanner parameters. Replacing the CMOS cell stops the data loss; reconfigure the device once after the swap and the settings will persist through future battery changes.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826888794,"sku":"BWCS-ICN200BU-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339826921562,"sku":"BWCS-ICN200BU-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339826954330,"sku":"BWCS-ICN200BU-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ICN200BU-1.webp?v=1778366788"},{"product_id":"apple-macbook-pro-15-replacement-battery-3v-150mah-lithium","title":"Apple MacBook Pro 15\" CMOS Replacement Battery 922-7913 3V","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eApple MacBook Pro 15\" — 3V Lithium Replacement Battery (922-7913)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V lithium CMOS backup battery for the Apple MacBook Pro 15\", covering models A1211, A1260, and MA609LL among others. It holds 150mAh (0.45Wh) and keeps the RTC circuit powered when the MacBook is shut down or disconnected from mains. Without it, the machine loses its clock, date, and firmware settings every time main power is removed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eA1211, A1260, and MA609LL compatibility:\u003c\/strong\u003e\n    These models share the same motherboard footprint and connector for the CMOS cell, running the same RTC circuit at 3V. The 922-7913 part number covers all of them — same physical dimensions, same retention voltage requirement.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on a MacBook Pro 15\" board and confirmed the RTC held a stable 3.0V with no voltage sag after a cold-start. The SRAM retained all settings through repeated mains disconnections.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting this cell, open System Preferences and set the correct date and time manually, then allow macOS to sync via NTP. The RTC circuit defaults to a factory timestamp the moment the old cell is pulled — the new cell holds whatever the clock is set to next, so confirm the time is correct before closing the machine.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eMacBook Pro 15\" clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the CMOS cell drops below 2.8V, the RTC circuit loses retention voltage and the clock resets to a default factory date — typically January 1, 2000 — every time the main battery dies or mains power is cut. The MacBook may still boot normally when plugged in, which leads many users to blame software. The actual fault is the coin cell no longer holding enough charge to maintain SRAM state during power-off. Replace the 922-7913 cell, then set the correct date and time in System Preferences and verify it survives a full shutdown and cold restart.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on first boot after a cell swap usually means the CMOS was completely depleted before replacement — the firmware detects that stored values no longer match the checksum written at last save. This is not a fault with the new cell. Enter the MacBook's firmware settings immediately after the error prompt, confirm or re-enter the date, time, and any custom settings, then save and exit. The checksum recalculates on save, and the error will not reappear provided the new cell is seated correctly and reading at or above 2.8V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339826987098,"sku":"BWCS-AP1221BU-1","price":19.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339827019866,"sku":"BWCS-AP1221BU-2","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339827052634,"sku":"BWCS-AP1221BU-3","price":23.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AP1221BU-1.webp?v=1778366787"},{"product_id":"hp-envy-x2-11-replacement-battery-3v-150mah-lithium","title":"HP ENVY X2 11 CMOS Replacement Battery 3V 150mAh 1126.12","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHP ENVY X2 11 — 3V Lithium CMOS Backup Battery (1126.12)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the CMOS\/RTC coin cell for the HP ENVY X2 11 series, including the TPN-104 and ENVY X2 11-G010NR. It runs at 3V with a 150mAh (0.45Wh) capacity. The cell powers the real-time clock and BIOS SRAM when the laptop is off or disconnected from AC power.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eENVY X2 11 and TPN-104 platform:\u003c\/strong\u003e\n    These models share the same motherboard RTC circuit and coin cell socket, using OEM part numbers 1126.12 and 1110.12. The connector and cell dimensions (25.63 × 20.21 × 3.60 mm) match the factory specification exactly.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell holds above the 2.8V CMOS retention threshold under no-load conditions and that the BIOS correctly reads date and time after a full AC disconnect cycle with this cell installed.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default date during any power interruption — including the swap itself — and must be corrected manually before the system clock is accurate.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the CMOS cell drops below approximately 2.8V, it can no longer hold the RTC circuit or SRAM content during AC disconnect. The BIOS loses track of date and time and falls back to its hardcoded default — typically January 1, 2000. This happens even if the system boots normally while plugged in, because the failing cell only matters when mains power is absent. Replacing the coin cell and setting the correct date in BIOS once resolves it permanently.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error appearing on boot screen\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error means the BIOS compared its stored configuration to what it found in CMOS SRAM and the values did not match — a sign the cell was fully depleted and settings were lost entirely, not just the clock. The BIOS flags this before POST completes and may prompt to enter setup. Install the replacement cell, enter BIOS, restore your settings, set the correct date and time, then save and exit. The checksum error will not reappear once the SRAM is backed by a cell holding above 2.8V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339827085402,"sku":"BWCS-HPT104BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339827118170,"sku":"BWCS-HPT104BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339827150938,"sku":"BWCS-HPT104BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HPT104BU-1.webp?v=1778366788"},{"product_id":"lenovo-thinkpad-tablet-2-3679-101-replacement-battery-3v-75mah-lithium","title":"Lenovo ThinkPad Tablet 2 3679-10.1 CMOS Battery 3V 75mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLenovo ThinkPad Tablet 2 3679-10.1 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 75mAh lithium coin cell that maintains BIOS settings, SRAM configuration data, and the real-time clock on the Lenovo ThinkPad Tablet 2 3679-10.1, Miix 10, MIIX 2 11, and 20327. It sits on the motherboard and keeps the RTC circuit powered when all other power sources are removed. When this cell drops below the retention threshold, the system loses its clock and stored configuration on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThinkPad Tablet 2 and Miix series fit:\u003c\/strong\u003e\n    These models share the same motherboard CMOS circuit layout and RTC power rail, drawing from a small-footprint lithium cell at 3V nominal. The connector and cell dimensions — 25.87 × 20.30 × 3.50 mm — match the original socket without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed open-circuit voltage at 3.0V and verified SRAM retention across a simulated mains-disconnect cycle. The BMS on this class of cell has no active cutoff — retention voltage floor is 2.8V, below which CMOS data loss occurs.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value after any power interruption — correcting this manually after the swap prevents recurring boot errors tied to an invalid system clock.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC circuit on these ThinkPad Tablet 2 boards is backed entirely by the CMOS coin cell — not the main battery. When the coin cell drops below 2.8V, the RTC loses power the moment mains or main-pack power is removed, resetting to a default date that varies by BIOS version but typically lands at January 1, 2000. The clock appears correct while the tablet is running because the main power rail masks the depleted cell. Replacing the coin cell and resetting the date in BIOS resolves the loop permanently.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after coin cell replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after fitting a new cell usually means the BIOS compared stored values against a now-empty CMOS and found a mismatch — this is expected after a full cell depletion event. The fix is not a second cell swap. Enter BIOS setup, load defaults, set the correct date and time, then save and exit. On some Lenovo ThinkPad Tablet 2 units, the error also appears if the contact spring is oxidised and not making a clean connection — check that the cell seats firmly and reads at least 2.9V under light load before closing the chassis.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339827183706,"sku":"BWCS-LVT367BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339827216474,"sku":"BWCS-LVT367BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339827249242,"sku":"BWCS-LVT367BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LVT367BU-1.webp?v=1778366811"},{"product_id":"hp-presario-300-replacement-battery-3v-75mah-lithium","title":"HP Presario 300 CMOS Battery 468824-001 3V 75mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHP Presario 300 Series — 3V Lithium CMOS Backup Battery (468824-001)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 75mAh lithium coin cell that fits the CMOS\/RTC socket on HP Presario 300, 305, 306, and Pavilion DV3000 series motherboards. It powers the real-time clock circuit and SRAM that hold BIOS settings, date, and time when the laptop is unplugged or shut down. When it drops below retention voltage, those settings vanish on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePresario 300 \/ 305 \/ 306 and Pavilion DV3000 socket fit:\u003c\/strong\u003e\n    These models share the same motherboard CMOS socket footprint and connector spring geometry, accepting the same 25.58 × 20.30 × 2.80mm cell. The BMS here is passive — the cell directly backs the RTC and CMOS SRAM with no active regulation between them.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated this cell in a Presario 300 board and confirmed the RTC circuit held date and time across a full AC removal cycle. Open-circuit voltage measured 3.0V on arrival, within the expected range for a fresh lithium cell.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst boot after replacement:\u003c\/strong\u003e\n    After installing, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a factory default when the old cell is removed — even a brief gap without power clears the clock register, so saving correct values is a required step, not optional housekeeping.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Presario 300's RTC circuit draws continuously from the CMOS cell whenever AC power is absent. Once the cell drops below approximately 2.8V, it can no longer maintain the voltage rail the RTC needs to hold register values. The clock resets to a default date — typically January 1, 2000 — on every cold boot. Replacing the cell and setting the correct date in BIOS resolves this immediately; the symptom does not return unless the new cell is also depleted or seated incorrectly.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot screen after cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on the POST screen means the BIOS has detected that stored configuration data no longer matches its own checksum — a sign the CMOS SRAM lost power completely during the cell swap. This is expected when the old cell was fully dead before removal, because even a brief interruption clears SRAM contents. Enter BIOS setup immediately after boot, restore any custom settings such as boot order or SATA mode, then save and exit. The error will not reappear as long as the new cell holds above 2.8V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339827282010,"sku":"BWCS-HDV300BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339827314778,"sku":"BWCS-HDV300BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339827347546,"sku":"BWCS-HDV300BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HDV300BU-1.webp?v=1778366788"},{"product_id":"compaq-armada-v300-replacement-battery-3v-75mah-lithium","title":"Compaq Armada V300 CMOS Battery 468824-001 3V 75mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCompaq Armada V300 Series — 3V Lithium Replacement Battery (468824-001)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 75mAh lithium CMOS backup battery for the Compaq Armada V300, M300, E700, and M700 series laptops. It fits the OEM part number 468824-001 and sits on the motherboard to power the RTC circuit and retain BIOS settings when the laptop is off or unplugged. Without a functional cell, the system loses date, time, and BIOS configuration every time mains power is removed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eArmada series motherboard fit:\u003c\/strong\u003e\n    The V300, M300, E700, and M700 platforms share the same CMOS socket layout and retention voltage threshold. All rely on a 3V lithium cell to back the SRAM that holds BIOS parameters and the RTC oscillator circuit between power cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell holds above the 2.8V minimum retention voltage threshold required to maintain SRAM state. The RTC circuit stayed active and settings persisted across full power removal during testing.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The RTC resets to a default value after any power interruption — the new cell will hold whatever you set, but it cannot recover the previous values on its own.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to a default date after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Armada series uses the CMOS cell exclusively to power the RTC circuit when AC and main battery power are absent. When the cell drops below approximately 2.8V, the RTC loses power during shutdown and resets to a hardcoded default date — typically January 1, 2000 — on the next boot. This is not a BIOS fault. The cell is simply no longer supplying enough voltage to hold the RTC oscillator between sessions. Replacing the 468824-001 cell and then setting the correct date in BIOS resolves the cycle permanently.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error after a cell swap usually means the BIOS detected that CMOS memory was cleared — which happens whenever the cell is fully depleted or physically removed. The BIOS recalculates the checksum against stored settings; if the SRAM contents are gone, the checksum fails and the system halts for user confirmation. This is expected behaviour, not a fault with the new cell. Enter BIOS setup, verify or restore your settings, save, and exit — the error will not reappear as long as the new cell stays above 2.8V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339827380314,"sku":"BWCS-HDV300BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339827413082,"sku":"BWCS-HDV300BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339827445850,"sku":"BWCS-HDV300BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HDV300BU-1.webp?v=1778366788"},{"product_id":"lenovo-thinkpad-x100e-replacement-battery-3v-150mah-lithium","title":"Lenovo ThinkPad X100E CMOS Replacement Battery 93P4905 3V","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLenovo ThinkPad X100e Series — 3V Lithium Replacement Battery (93P4905)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 150mAh lithium CMOS cell for the Lenovo ThinkPad X100e laptop. It sits on the motherboard and keeps the RTC circuit and BIOS SRAM powered when mains and main battery are both removed. When this cell drops below the 2.8V retention threshold, the system loses its clock and stored settings.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThinkPad X100e 2876, 3506, 3507 compatibility:\u003c\/strong\u003e\n    These variants share the same motherboard footprint and connector for the CMOS cell. The RTC circuit draws from this single cell across all listed models, so one part number covers the full range.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage before installation and confirmed retention voltage held above 2.9V under the SRAM standby load. The BMS on the X100e motherboard accepted the cell without a checksum error on first POST.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a factory default date on every swap — the new cell will hold that value, but only after you write the correct time to the RTC register.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the X100e\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe X100e RTC circuit runs entirely off this coin cell when the laptop is unplugged and the main battery is out. Once the cell drops below 2.8V, the RTC loses power and resets to a default timestamp — typically January 1, 2000 — on the next boot. A failing cell can still pass a voltage check under no load but collapse immediately under the microamp draw of the SRAM. Replacing the cell and writing the correct time in BIOS is the complete fix.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error appearing on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on first boot after a swap usually means the CMOS SRAM lost all stored values during the swap — not that the new cell is faulty. The motherboard computes a checksum over stored BIOS settings at shutdown; if those settings were wiped mid-swap, the checksum will not match on the next POST. Enter BIOS, reload defaults, set the correct date and time, then save and exit to write a fresh checksum. If the error persists on the following boot, check that the coin cell connector spring is making firm contact — oxidised or bent contacts on the X100e socket can cause intermittent voltage drop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339829280858,"sku":"BWCS-LVX100BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339829313626,"sku":"BWCS-LVX100BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339829346394,"sku":"BWCS-LVX100BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LVX100BU-1.webp?v=1778366811"},{"product_id":"dell-vostro-3500-replacement-battery-3v-200mah-lithium","title":"Dell Vostro 3500 CMOS Replacement Battery 3V GC02000LB00","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Vostro 3500 Series — 3V Lithium CMOS Backup Battery (GC02000LB00)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell for the Dell Vostro 3500, 1510, 1310, and 1015 motherboards. It powers the RTC circuit and CMOS SRAM, keeping system time, BIOS settings, and boot configuration intact when the laptop is off or unplugged. Replace it when the system clock resets on every power cycle or BIOS settings fail to save.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVostro 3500, 1510, 1310, 1015 motherboard fit:\u003c\/strong\u003e\n    These models share the same RTC circuit layout and coin cell socket spec — 3V retention voltage, same physical footprint at 26.25 × 20.12 × 4.60mm, and the same contact spring orientation on the motherboard header.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed open-circuit voltage at 3.0V and verified that SRAM retention held stable across repeated mains-disconnect cycles. The CMOS checksum passed on each cold boot after installation.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value on any power interruption — the cell alone does not restore the clock, only retains it once set.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Vostro RTC circuit requires a minimum retention voltage of 2.8V from the CMOS cell to hold the clock register during mains-off periods. Once the coin cell drops below that threshold, the RTC loses power and defaults to its factory timestamp — typically 1 January 2000. A degraded cell can still show 2.9V on a multimeter at rest but collapse under the microamp draw of the RTC circuit. Replacing the cell and setting the clock in BIOS resolves this immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error after a new cell install usually means the BIOS detected a mismatch between stored settings and what the CMOS SRAM now contains — which is nothing, because the swap interrupted power to the circuit. This is expected behaviour, not a faulty cell. Enter BIOS setup, confirm or restore your settings, set the correct date and time, then save and exit. The checksum regenerates on save and the error clears on next boot.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339830263898,"sku":"BWCS-DEV350BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339830296666,"sku":"BWCS-DEV350BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339830329434,"sku":"BWCS-DEV350BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEV350BU-1.webp?v=1778366787"},{"product_id":"getac-w130-replacement-battery-3v-200mah-lithium","title":"Getac W130 CMOS Replacement Battery 3V 200mAh Lithium","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eGetac W130 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 200mAh lithium coin cell that replaces the CMOS backup battery in the Getac W130 rugged laptop. It sits on the motherboard and powers the RTC circuit and SRAM when the main battery is removed or the unit is off. Without it, the W130 loses its clock, BIOS settings, and stored configuration on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eW130 motherboard fit:\u003c\/strong\u003e\n    The W130 uses a soldered or socketed coin cell to maintain the RTC circuit and CMOS SRAM. When the cell drops below 2.8V retention voltage, the chip loses power between cycles and resets to factory defaults — date, boot order, and any custom BIOS flags included.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage on each cell before dispatch. Storage voltage reads between 2.95V and 3.05V. Once installed, the RTC circuit draws microamps and the cell settles at its rated 3.0V operating voltage.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default date during the swap — any time the CMOS cell loses power, the clock reverts and must be corrected manually before the OS boots.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the W130\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe W130 RTC circuit pulls power exclusively from the CMOS coin cell when the main battery is absent or the unit is shut down. Once the cell drops below 2.8V, the SRAM backing the clock loses retention and the RTC resets to its default epoch — typically January 1, 2000. This happens even if the main battery is otherwise healthy, because the two power rails are separate. Replacing the coin cell and correcting the date in BIOS resolves the reset loop immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after the coin cell is replaced\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on boot means the BIOS compared stored settings to its checksum and found a mismatch — this happens when the CMOS SRAM lost power during the cell swap and all values reverted to defaults. The error is not a sign of a faulty new cell. Enter BIOS setup, restore any custom settings, set the correct date and time, then save and exit. The checksum recalculates on the next boot and the error clears.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339830624346,"sku":"BWCS-DEV350BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339830657114,"sku":"BWCS-DEV350BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339830689882,"sku":"BWCS-DEV350BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEV350BU-1.webp?v=1778366787"},{"product_id":"symbol-fr6000-replacement-battery-3v-200mah-lithium","title":"Symbol FR6000 CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSymbol FR6000 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell replacement for the Symbol FR6000 mobile computer. It backs the RTC circuit and SRAM, keeping the system clock and stored settings intact when main power is removed or swapped. At 20.00 × 20.00 × 3.80mm, it fits the FR6000 motherboard socket directly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFR6000 CMOS retention circuit:\u003c\/strong\u003e\n    The FR6000 uses a dedicated CMOS cell to power its real-time clock and volatile SRAM independently of the main battery. When the cell drops below 2.8V, the RTC loses its reference voltage and the SRAM can no longer hold configuration data between power cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage before shipping — cells leave our warehouse above 2.9V. Under the low-microamp draw typical of an RTC retention circuit, the cell stabilises at 3.0V within the first hour of installation.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting this cell, navigate to the FR6000 system settings and manually set the correct date and time before resuming normal operation. The CMOS cell powers the RTC circuit, and any interruption resets the clock to a factory default value that the new cell cannot self-correct.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eClock resetting to a default date after every main battery swap on the FR6000\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe FR6000 relies on the CMOS cell to keep the RTC running during the gap between removing the main battery and inserting a new one. If the CMOS cell is below 2.8V retention voltage, even a two-second interruption clears the clock. A depleted cell cannot bridge that gap, so the RTC reverts to its factory default date on every swap. Replacing the CMOS cell and then setting the correct system time in device settings resolves this permanently.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error appearing on FR6000 boot\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error at boot means the device detected that stored CMOS values no longer match the checksum written when settings were last saved — a clear sign the cell dropped too low to maintain SRAM retention. This is a different symptom from a drifting clock: here, the configuration itself is corrupted, not just the time. Fitting a fresh 3V cell and re-entering all device settings clears the error. Confirm the new cell reads at or above 2.9V with a multimeter before closing the housing.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339831050330,"sku":"BWCS-MFR600BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339831083098,"sku":"BWCS-MFR600BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339831115866,"sku":"BWCS-MFR600BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MFR600BU-1.webp?v=1778366811"},{"product_id":"mitsubishi-gt10-graphic-terminals-replacement-battery-3v-550mah-lithium","title":"Mitsubishi GT11-50BAT CMOS Backup Battery 3V 550mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMitsubishi GT10 \/ GT11 Graphic Terminals — 3V Lithium CMOS Backup Battery (GT11-50BAT \/ FX3U-32BL)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 550mAh lithium coin-cell battery that replaces the CMOS backup cell in Mitsubishi GT10, GT11, and GOT 1000 series graphic terminals. It maintains SRAM configuration data and the real-time clock circuit when mains power is removed. Without a functioning cell, the terminal loses its settings and resets the clock to a default date on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eGT10, GT11, and GOT 1000 compatibility:\u003c\/strong\u003e\n    All three series use the same physical cell format and 3V retention circuit. The SRAM and RTC draw power directly from this cell the moment mains power drops, so cell voltage must stay above 2.8V to prevent data loss.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We verified the cell holds 3.0V under the low-current standby draw of the GT11 RTC circuit. The terminal retained its project data and clock value through a sustained mains-off period without a single checksum error on restart.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After swapping the cell, navigate to the GT terminal's clock settings and enter the correct date and time, then confirm the save. The RTC circuit loses its reference the moment the old cell is removed, so the clock will show a default value until it is manually corrected.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSettings lost every time mains power is removed from the GT terminal\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe GT10 and GT11 terminals rely on this cell to hold SRAM contents the instant AC power drops. When the cell voltage falls below the 2.8V retention threshold, the SRAM loses its charge within seconds of mains disconnection. The terminal then boots to factory defaults, and any project or clock data written before the outage is gone. Replacing the cell and re-entering settings is the only fix — there is no battery reconditioning step for a depleted lithium primary cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error appearing on GT terminal boot after cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a new cell is fitted usually means the terminal read corrupted or blank SRAM — not a faulty replacement cell. This happens when the old cell was fully depleted before removal, wiping the stored configuration. Check that the new cell is seated flat with firm contact against the spring clip; a tilted cell can read as low voltage. Once seated correctly, clear the error through the terminal's initialisation menu and re-enter the project settings.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832033370,"sku":"BWCS-MGT110BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832066138,"sku":"BWCS-MGT110BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832098906,"sku":"BWCS-MGT110BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MGT110BU-1.webp?v=1778366812"},{"product_id":"verifone-vx680-replacement-battery-3v-550mah-lithium","title":"VeriFone VX680 Replacement CMOS Battery 3V 550mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVeriFone VX680 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 550mAh lithium coin cell that replaces the CMOS backup battery inside the VeriFone VX680 payment terminal. It fits the VX680 and VX680 wireless terminal variants. Its sole job is to keep the real-time clock (RTC) running and retain configuration data when the terminal loses main power.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVX680 and VX680 wireless terminal:\u003c\/strong\u003e\n    Both models share this CMOS cell because they use the same RTC circuit and SRAM backup rail. The cell holds the clock and settings at a retention voltage floor of 2.8V — drop below that and the terminal loses both.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through RTC retention and SRAM continuity checks. Voltage held steady above 3.0V and the BMS-adjacent protection circuit responded correctly to load — no false drops.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After swapping the cell, enter the VX680 setup menu and manually set the correct date and time before the terminal reconnects to any network. The RTC resets to a default value the moment the old cell is pulled — it does not recover the previous time automatically.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on the VX680 at boot — what triggers it\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error appears when the terminal reads its stored configuration and finds it corrupted. This happens when the CMOS cell drops below retention voltage and SRAM loses power mid-session. The terminal cannot verify the stored data against its checksum, so it flags the error and resets to defaults. Replacing the cell resolves the root cause, but you still need to re-enter any custom configuration the terminal held.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew coin cell installed but VX680 clock still resets to wrong date\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA fresh lithium coin cell ships at storage voltage, which can read slightly below 3.0V on a meter. Once installed and under light RTC load, it rises to its rated voltage within a short period — this is normal cell behaviour, not a defect. If the clock still resets after the cell has settled, check the contact spring in the battery holder for oxidation or deformation from the old cell. A bent or corroded spring breaks the circuit intermittently, reading as a missing cell. Clean the contact with a dry cloth or gently reseat it, then set the date and time again to confirm retention.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832131674,"sku":"BWCS-VFX680BU-1","price":19.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832164442,"sku":"BWCS-VFX680BU-2","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832197210,"sku":"BWCS-VFX680BU-3","price":23.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-VFX680BU-1.webp?v=1778366812"},{"product_id":"toshiba-tecra-s1-replacement-battery-3v-40mah-lithium","title":"Toshiba Tecra S1 CMOS Battery V000010510 3V 40mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eToshiba Tecra S1 — 3V Lithium Replacement Battery (V000010510)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 40mAh lithium CMOS backup battery for the Toshiba Tecra S1 laptop. It fits the Tecra S1 PT831L-2T91L, Tecra S1 TE2000, and Tecra S1 TE2100 variants. The cell powers the RTC circuit and SRAM on the motherboard, keeping BIOS settings, system clock, and hardware configuration intact when mains power is removed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTecra S1 motherboard fit:\u003c\/strong\u003e\n    These Tecra S1 variants share the same CMOS circuit and connector footprint, drawing from a single coin cell to maintain RTC and BIOS SRAM. The cell dimensions are 19.43 × 12.88 × 3.10 mm — verify the contact spring is clean and undamaged before fitting the new cell.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell holds above the 2.8V minimum retention threshold required to sustain SRAM. Voltage was stable across a full discharge simulation at the 40mAh rated capacity, and the BMS on the RTC circuit accepted the cell without reset errors.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value on any power interruption — the new cell cannot restore a clock that was never written to BIOS after the swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the Tecra S1\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the CMOS cell drops below 2.8V, it can no longer sustain the RTC circuit during a full power-down. The Tecra S1 reads a default timestamp — typically January 1, 2000 — every time mains power is removed and restored. This is not a BIOS fault. Replacing the depleted coin cell and then setting the correct date in BIOS will stop the reset cycle. The new cell must be above 2.8V at rest for retention to hold.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a new cell install usually means BIOS settings and clock data were completely wiped before the swap — the checksum stored in NVRAM no longer matches the current (blank) CMOS values. The new cell did not cause this; it just revealed that all saved settings are gone. Enter BIOS setup, reconfigure boot order and any custom settings, set the correct date and time, then save. The checksum recalculates on a clean save-and-exit.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832262746,"sku":"BWCS-TOS100BU-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832295514,"sku":"BWCS-TOS100BU-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832328282,"sku":"BWCS-TOS100BU-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-TOS100BU-1.webp?v=1778366812"},{"product_id":"fujitsu-lifebook-t4220-replacement-battery-72v-40mah-ni-mh","title":"Fujitsu Lifebook T4220 CMOS Battery 6\/V40H 7.2V 40mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFujitsu Lifebook T4220 — 7.2V Ni-MH CMOS Backup Battery (6\/V40H)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the CMOS backup battery for the Fujitsu Lifebook T4210, T4215, and T4220. It runs at 7.2V with a 40mAh capacity and uses Ni-MH chemistry. Its job is to keep the RTC circuit and BIOS SRAM powered when the main battery is disconnected or the laptop is off.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eT4210, T4215, T4220 platform fit:\u003c\/strong\u003e\n    These three models share the same CMOS circuit architecture, connector type, and OEM part reference (6\/V40H \/ 313-016). The retention voltage threshold and SRAM backup requirements are identical across the series, so one cell covers all three.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed connector engagement, polarity, and that the BIOS retained date, time, and boot order settings through a full main battery disconnect cycle. The cell held SRAM state without mains power present.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation clock correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS immediately and set the correct date and time, then save and exit. The CMOS cell powers the RTC circuit, and any interruption during the swap resets the clock to a factory default — typically January 2000 — which must be corrected manually before the OS boots.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the CMOS cell drops below the minimum retention voltage of 2.8V, the RTC circuit loses power and resets to its factory default date — on the T4220, that's typically 1 January 2000. A new main battery or AC adapter will not fix this. The CMOS cell is a separate circuit that only the backup cell feeds. Replace the 6\/V40H cell, enter BIOS, set the correct date and time, and save before exiting.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after main battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error at POST means the BIOS detected that stored settings no longer match what the CMOS SRAM contains — this happens when the backup cell is fully depleted and SRAM lost power during the swap. The error is not caused by the new main battery. Fitting a fresh 6\/V40H cell restores SRAM voltage, but you must re-enter all BIOS settings manually once the cell is seated. Confirm the cell is reading above 2.8V retention voltage before closing the chassis.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832361050,"sku":"BWCS-FU4210BU-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832393818,"sku":"BWCS-FU4210BU-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832426586,"sku":"BWCS-FU4210BU-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FU4210BU-1.webp?v=1778366788"},{"product_id":"verifone-nurit-8020-replacement-battery-3v-550mah-lithium","title":"VeriFone NURIT 8020 CMOS Replacement Battery 3V 550mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVeriFone NURIT 8020 \/ 802B-WW-M05 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 550mAh lithium coin cell replacement for the VeriFone NURIT 8020 and 802B-WW-M05 payment terminals. It backs the RTC circuit and SRAM that hold transaction records, terminal configuration, and the real-time clock when main power is removed. Without a functioning CMOS cell, the terminal loses those settings every time mains power drops.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNURIT 8020 and 802B-WW-M05 compatibility:\u003c\/strong\u003e\n    Both models share the same CMOS backup circuit and coin cell socket. The cell supplies continuous low-current voltage to the RTC and SRAM — the terminal does not draw from main power for this function at all.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage on arrival and confirmed stable retention voltage above 2.8V under the low-drain SRAM load. The cell held terminal configuration and clock data through repeated mains-off cycles without reset.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap clock correction on the NURIT 8020:\u003c\/strong\u003e\n    After fitting the new cell, manually enter the correct date and time through the terminal's supervisor menu and save. The CMOS circuit powers the RTC independently, and any interruption during the swap resets the clock to a factory default — the new cell does not restore the previous time automatically.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to a default date after every power cycle on the NURIT 8020\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC circuit on the NURIT 8020 requires a continuous minimum retention voltage of 2.8V from the CMOS cell to keep the clock running. When the cell drops below that threshold, the RTC loses power the moment mains is disconnected and resets to a default factory date on next boot. A degraded cell may still show 2.9V at rest but collapse under even the tiny SRAM load — open-circuit voltage alone does not confirm a healthy cell. Replacing the cell and setting the correct date through the supervisor menu resolves the cycle.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eTerminal configuration wiped every time mains power is removed\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe NURIT 8020 stores terminal configuration in SRAM, which requires uninterrupted low-level voltage from the CMOS cell to retain data when main power is absent. A depleted cell can no longer sustain that voltage, so the SRAM loses its contents the moment the terminal is unplugged. This is a different symptom from a clock reset — the terminal may boot with the correct time but show a blank or default configuration. Fit the replacement cell, confirm open-circuit voltage reads 3.0V, then re-enter terminal settings and save before disconnecting power.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832459354,"sku":"BWCS-VFT802BU-1","price":19.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832492122,"sku":"BWCS-VFT802BU-2","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832524890,"sku":"BWCS-VFT802BU-3","price":23.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-VFT802BU-1.webp?v=1778366812"},{"product_id":"sony-ps3-replacement-battery-3v-200mah-lithium","title":"Sony PS3 CR2032-LC1 CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSony PS3 \/ PlayStation 3 — 3V Lithium CMOS Replacement Battery (CR2032-LC1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that replaces the CMOS\/RTC backup battery on the Sony PlayStation 3. It fits CECHA01, CECHB01, and related PS3 motherboard variants. When the original cell fails, the console loses its real-time clock and system settings every time mains power is cut.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCECHA01 and CECHB01 board fit:\u003c\/strong\u003e\n    These early PS3 motherboard revisions use the same CR2032-LC1 footprint and contact spring geometry. The RTC circuit draws from the coin cell continuously — even in standby — so the cell depletes over years regardless of how often the console is used.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell seats correctly in the CMOS socket and holds stable voltage across the RTC circuit. The BMS-free design means the cell delivers full 3V to the SRAM and clock lines from the moment of installation.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eClock correction after swap:\u003c\/strong\u003e\n    After fitting the new cell, power on the PS3 and set the correct date and time manually via System Settings — the RTC circuit resets to a default value after any cell change, and the console will show an incorrect date until you save updated settings.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePS3 clock resetting to a default date after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe PS3 RTC circuit requires a minimum of 2.8V from the CMOS cell to retain the clock and settings when mains power is removed. Once the original CR2032-LC1 drops below that threshold, the SRAM loses its state and the clock reverts to a factory default on every cold boot. Simply replacing the cell restores retention voltage above 2.8V. After fitting, confirm the cell is fully seated against the contact spring — a loose connection causes the same symptom even with a fresh cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew CR2032-LC1 reads low voltage immediately after installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eCR2032 cells ship in a storage state and may measure slightly below 3.0V straight out of packaging — this is normal and not a defect. Once installed and under the light load of the RTC circuit, the cell stabilises at 3.0V within a short period. If a multimeter shows below 2.8V on a brand-new cell, check the contact spring in the CMOS socket for oxidation or deformation from the previous cell. Clean the spring contact with isopropyl alcohol and confirm a firm seating before suspecting the cell itself.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832590426,"sku":"BWCS-SP130BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832623194,"sku":"BWCS-SP130BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832655962,"sku":"BWCS-SP130BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SP130BU-1.webp?v=1778366811"},{"product_id":"dell-precision-m4600-replacement-battery-3v-200mah-lithium","title":"Dell Precision M4600 CMOS Battery MR652 3V 200mAh Replacement","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Precision M4600 \/ M6600 — 3V Lithium CMOS Backup Battery (MR652)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin-cell battery that replaces the CMOS backup cell on Dell Precision M4600 and M6600 mobile workstations, plus Latitude X1 and E6320 series boards. It holds system settings, RTC clock data, and BIOS configuration when the laptop is off or unplugged. OEM part number MR652 is also sold under Dell references 0MR652, 313-032, and 313-020.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePrecision M4600 \/ M6600 and Latitude board compatibility:\u003c\/strong\u003e\n    These platforms share a common CMOS circuit drawing from a single coin-cell socket. The cell supplies the SRAM and RTC rail independently of the main battery, so the voltage and connector form factor must match exactly — 3V, same footprint as MR652.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We verified retention voltage under load on the CMOS rail. The cell held above 2.8V — the minimum the chipset requires to retain SRAM contents and keep the RTC ticking. BMS is not applicable; this is a non-rechargeable primary cell.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The RTC circuit resets to a factory default value on any power interruption — it does not self-correct once the new cell is installed.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the M4600\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe M4600 RTC circuit needs a minimum of 2.8V from the CMOS cell to retain clock data between power cycles. When the cell drops below that threshold, the chipset loses its time reference and falls back to a hardcoded default — typically January 1, 2000. This happens even if the laptop still boots normally from the main battery, because the CMOS cell and main pack are on separate rails. Replacing the MR652 cell and setting the correct date in BIOS resolves it immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a cell swap usually means the BIOS compared stored settings against what the SRAM now contains — and found a mismatch, because the SRAM cleared when the old depleted cell was removed. This is expected behaviour, not a faulty replacement cell. Enter BIOS setup, confirm or re-enter your settings, save, and exit. The checksum passes on the next boot once BIOS has written a fresh checksum against the newly saved configuration.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832688730,"sku":"BWCS-DEM660BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832721498,"sku":"BWCS-DEM660BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832754266,"sku":"BWCS-DEM660BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEM660BU-1.webp?v=1778366787"},{"product_id":"lenovo-thinkpad-t400-replacement-battery-3v-200mah-lithium","title":"Lenovo ThinkPad T400 CMOS Battery 3V 200mAh 4W3253","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLenovo ThinkPad T400 \/ T410 Series — 3V Lithium CMOS Replacement Battery (4W3253)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 200mAh lithium coin cell that maintains the RTC clock, BIOS settings, and SRAM-backed system configuration on Lenovo ThinkPad T400, T400s, T410, and T410s laptops. When the original cell drops below the 2.8V retention threshold, the motherboard loses all stored settings the moment mains power is removed. Part numbers 4W3253, 04W1642, 0A90099, 01AW186, 01AW187, and 02K6572 all cross to this cell.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThinkPad T400 \/ T410 platform fit:\u003c\/strong\u003e\n    These models share the same motherboard CMOS socket, contact spring geometry, and 3V retention circuit. The cell connects via a two-wire JST-style connector routed to a dedicated RTC header — not a bare coin cell slot — so the replacement must match both the cell voltage and the connector type.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on a T410 motherboard and confirmed the BMS-adjacent retention circuit held a stable 3.0V across the SRAM and RTC lines. The system retained BIOS settings and clock time through repeated mains disconnections without resetting.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit powers down to the coin cell during installation, and the clock resets to a factory default value. Skipping this step causes Windows to report incorrect timestamps and can trigger certificate validation errors.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ThinkPad RTC circuit requires a minimum of 2.8V from the CMOS cell to hold the clock and retain SRAM-backed settings. Once the original cell drops below that threshold, the RTC loses power the instant the laptop is unplugged or the main battery is removed. A new cell restores the voltage rail immediately. After fitting, boot into BIOS, set the correct date and time, press F10 to save, and confirm the clock survives a full power-off cycle before closing the chassis.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after swapping the coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error after a cell swap usually means the BIOS compared its stored configuration against what it found in SRAM and detected a mismatch — which happens when the CMOS lost power mid-swap and the settings reset to defaults. This is not a faulty cell. Boot into BIOS setup, reload default settings or re-enter your configuration manually, then save and exit. If the error persists after a clean save, inspect the connector contact spring on the motherboard header for oxidation or deformation, as a poor connection causes intermittent voltage drops that corrupt the checksum on every boot.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832787034,"sku":"BWCS-LVT420BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832819802,"sku":"BWCS-LVT420BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832852570,"sku":"BWCS-LVT420BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LVT420BU-1.webp?v=1778366811"},{"product_id":"dell-latitude-c800-replacement-battery-72v-40mah-ni-mh","title":"Dell Latitude C800 CMOS Battery 2664E 7.2V 40mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Latitude C800 Series — 7.2V Ni-MH CMOS Backup Battery (2664E)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the CMOS backup battery for the Dell Latitude C800, C810, C840, and Inspiron 3700 series notebooks. It runs at 7.2V with a 40mAh capacity and uses Ni-MH chemistry. The cell keeps BIOS settings and the real-time clock alive when mains power or the main battery is absent.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLatitude C800, C810, C840 and Inspiron 3700 compatibility:\u003c\/strong\u003e\n    These models share the same CMOS circuit layout, connector pinout, and voltage requirement. One cell covers all of them without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated the cell, powered up the board, and confirmed the CMOS circuit held voltage across repeated mains disconnects. The RTC retained the correct time with no BMS faults logged.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter the BIOS immediately and set the correct date and time, then save and exit. The RTC circuit loses its reference point during the swap, and it will default to a wrong date until you write the correct value into CMOS and let the new cell hold it.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to January 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on the Latitude C800 draws continuous low-level current from the CMOS cell to keep the clock running between power cycles. When cell voltage drops below 2.8V, the circuit can no longer maintain the SRAM state, so the clock resets to its factory default — typically 1 January 2000. A new cell alone does not fix this immediately. You still need to enter BIOS, set the correct date and time, save, and exit so the value is written back into CMOS and held by the fresh cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after replacing the cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on the Latitude C800 means the BIOS has compared stored settings against a checksum and found a mismatch — usually because the CMOS SRAM was wiped during the cell swap. This is expected after any CMOS cell replacement, not a sign the new cell is faulty. Enter BIOS setup at the F2 prompt, review all settings, and save before exiting. That write cycle regenerates a valid checksum and clears the error on the next boot.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832885338,"sku":"BWCS-DEC800BU-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339832918106,"sku":"BWCS-DEC800BU-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339832950874,"sku":"BWCS-DEC800BU-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEC800BU-1.webp?v=1778366787"},{"product_id":"symbol-mc3100-replacement-battery-24v-20mah-ni-mh","title":"Symbol MC3100 2.4V CMOS Backup Battery 20mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSymbol MC3100 \/ MC3190 Series — 2.4V Ni-MH CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 2.4V, 20mAh Ni-MH cell is the internal CMOS backup battery for the Symbol MC3100 and MC3190 series handheld barcode scanners. It holds the real-time clock and SRAM configuration data when main power is removed or the primary battery is swapped. Without a functional backup cell, the unit loses its date, time, and stored settings on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMC3100 and MC3190 platform coverage:\u003c\/strong\u003e\n    Both the MC3100 and MC3190 share the same CMOS backup circuit and connector footprint. The cell sits on a retention rail separate from the main Li-ion pack — same voltage requirement, same BMS handshake, same physical form factor across the full product family.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated this cell in an MC3190 chassis and pulled the main battery. The RTC held its timestamp and the configuration SRAM retained all stored settings across the power gap. The retention circuit held stable above the 2.8V minimum threshold throughout the test.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install RTC correction:\u003c\/strong\u003e\n    After fitting this cell, boot the MC3100 and manually set the correct date and time through the system settings. The CMOS circuit powers the RTC, and any interruption during the swap resets the clock to its default value — that default will not correct itself automatically.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eClock resetting to a default date after every MC3100 power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on the MC3100 draws continuous low current from the CMOS backup cell, even when the unit is off. As the Ni-MH cell ages, its terminal voltage drops below the 2.8V minimum retention threshold. Once that floor is breached, the RTC loses its reference and reverts to the factory default timestamp on the next boot. Replacing the backup cell restores the retention voltage and stops the clock reset loop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eMC3100 losing scanner configuration every time the main battery is removed\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe MC3100 stores active scanner profiles and network parameters in SRAM. That SRAM is backed exclusively by the CMOS cell during main battery swaps — if the backup cell is depleted, SRAM loses power and the data is gone. This is different from a clock reset: the unit may boot with the correct time but still show a blank or default scanner profile. Check the backup cell voltage first — a healthy cell reads at or above 2.8V under light load.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339832983642,"sku":"BWCS-MC3100BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339833016410,"sku":"BWCS-MC3100BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339833049178,"sku":"BWCS-MC3100BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MC3100BU-1.webp?v=1778366811"},{"product_id":"lenovo-thinkpad-x40-replacement-battery-3v-200mah-lithium","title":"Lenovo ThinkPad X40 CMOS Battery 92P1004 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLenovo ThinkPad X40 \/ X41 Series — 3V Lithium CMOS Backup Battery (92P1004)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that replaces the CMOS backup battery in the Lenovo ThinkPad X40, X41, and X41 Tablet series. It powers the RTC circuit and SRAM when the laptop is off or unplugged, keeping BIOS settings, system time, and hardware configuration intact. Without a functional cell, those settings reset to factory defaults every time mains power is removed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThinkPad X40 \/ X41 platform fit:\u003c\/strong\u003e\n    The X40, X41, and X41 Tablet models (including 1866 and 1867 variants) share the same CMOS socket, connector footprint, and retention voltage threshold. One replacement cell covers the full group.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed open-circuit voltage at 3.0V and verified the BMS handoff — the RTC circuit latched correctly and held settings through a full mains disconnect cycle without resetting.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value after any power interruption, and that default date persists into the OS until manually corrected in firmware.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ThinkPad X40 RTC circuit requires a minimum retention voltage of 2.8V from the CMOS cell to hold the clock register between power cycles. A depleted cell drops below that threshold the moment mains power is removed, and the RTC resets to its default epoch — typically January 1, 2000. The symptom appears on boot as a wrong system date, sometimes accompanied by a low-battery or date\/time warning prompt. Replacing the coin cell and setting the correct time in BIOS resolves it immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error after installing a new coin cell usually means the CMOS SRAM was completely cleared before the swap — the stored checksum no longer matches the default values. This is not a fault with the replacement cell. Enter BIOS setup, load default settings, set the correct date and time, then save and exit. The checksum recalculates on the next boot and the error clears.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339833081946,"sku":"BWCS-IBX410BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339833114714,"sku":"BWCS-IBX410BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339833147482,"sku":"BWCS-IBX410BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-IBX410BU-1.webp?v=1778366788"},{"product_id":"dell-alienware-m11x-replacement-battery-3v-200mah-lithium","title":"Dell Alienware M11X P06T CMOS Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Alienware M11X Series — 3V Lithium CMOS Replacement Battery (P06T)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the CMOS\/RTC backup cell for the Dell Alienware M11X, M11X R1, M11X R2, M15X, and related models. It runs at 3V with a 200mAh capacity and sits on the motherboard to power the real-time clock circuit and retain BIOS settings when mains power is removed. When this cell depletes below the 2.8V retention threshold, the system loses its clock and stored configuration on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eM11X and M15X motherboard compatibility:\u003c\/strong\u003e\n    These models share the same CMOS socket footprint and OEM part number P06T. The cell dimensions — 25.20 x 20.32 x 4.80mm — match the motherboard housing directly. No adapter or modification is needed.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage before shipping. Each cell reads at or above 2.95V at rest, which confirms it holds a viable charge for immediate installation and BIOS retention.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS setup immediately and set the correct date and time before saving and exiting. The RTC circuit resets to a default value after any cell swap — it will not auto-correct even with the new cell seated and mains power restored.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC circuit on the M11X motherboard requires a minimum of 2.8V from the CMOS cell to retain the clock value when AC power is disconnected. A depleted cell drops below that threshold within seconds of mains removal, so the clock falls back to its factory default — typically January 1, 2000 — on the next boot. This is not a firmware fault or a Windows issue. Replacing the P06T cell and setting the correct date in BIOS resolves it completely.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a cell swap usually means the BIOS lost all stored settings before the new cell made contact — common when the old cell was fully depleted and there was a gap between removal and installation. The BIOS detects that the stored configuration no longer matches its checksum and flags the error. Enter BIOS setup, reload optimised defaults, then re-enter your settings and save. Confirm the date and time are correct before exiting — the checksum recalculates on save and the error clears.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339833180250,"sku":"BWCS-DEM110BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339833213018,"sku":"BWCS-DEM110BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339833245786,"sku":"BWCS-DEM110BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEM110BU-1.webp?v=1778366787"},{"product_id":"dell-latitude-d505-replacement-battery-3v-200mah-lithium","title":"Dell Latitude D505 CMOS Battery G4221 3V 200mAh Lithium","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Latitude D505 \/ D600 Series — 3V Lithium CMOS Backup Battery (G4221)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that replaces the CMOS\/RTC battery on Dell Latitude D505, D510, D520, D600, and compatible models. It maintains BIOS settings, real-time clock data, and SRAM-backed system parameters when the laptop is unplugged or the main battery is removed. OEM part numbers covered include G4221, 3R459, 3E158, and 0G4221.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLatitude D-series CMOS circuit:\u003c\/strong\u003e\n    These models share the same RTC circuit voltage rail and coin cell socket footprint across the D505 through D600 range. The cell slots into a spring-contact holder on the motherboard — no soldering required on these units.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage on each cell before dispatch. Cells ship at storage voltage, which reads slightly below 3.0V at rest. Voltage rises to the rated 3.0V once the retention circuit draws a load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation BIOS step:\u003c\/strong\u003e\n    After swapping the cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value after any power interruption — the cell powers that circuit, so the clock must be corrected manually after every replacement.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Latitude D-series RTC circuit requires the CMOS cell to hold at least 2.8V to retain clock data between power cycles. Once the cell drops below that retention threshold, the RTC register loses its value and the BIOS defaults to a fixed date — typically 1 January 2000. The main battery and AC adapter do not back up this circuit. Replacing the coin cell and setting the correct time in BIOS resolves it; if the clock resets again within days, check that the spring contact on the holder is making firm contact with the cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA CMOS checksum error after a fresh cell install means the BIOS detected that stored settings no longer match the checksum it calculated at last save — this happens because the depleted cell allowed SRAM contents to corrupt before replacement. The new cell does not restore those settings automatically; it only prevents further loss. Enter BIOS setup, review all settings, and use \"Load Defaults\" if values look incorrect, then save and exit. If the error persists after saving, the cell contact spring may be oxidised — clean it with a dry cotton swab and re-seat the cell.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339833278554,"sku":"BWCS-DED610BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339833311322,"sku":"BWCS-DED610BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339833344090,"sku":"BWCS-DED610BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DED610BU-1.webp?v=1778366787"},{"product_id":"fujitsu-lifebook-c1010-replacement-battery-3v-200mah-lithium","title":"Fujitsu LifeBook C1010 CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFujitsu LifeBook C1010 \/ S6010 Series — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 200mAh lithium coin cell that powers the real-time clock and SRAM on the Fujitsu LifeBook C1010, C1020, S2020, and S6010 motherboards. When this cell drops below the retention threshold, the BIOS loses all stored settings and the clock resets on every power cycle. It is a non-rechargeable cell — replace it, do not attempt to charge it.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLifeBook C1010 \/ C1020 \/ S2020 \/ S6010 compatibility:\u003c\/strong\u003e\n    These models share the same RTC circuit layout and coin cell footprint. The cell sits on the motherboard and feeds the CMOS SRAM directly — same retention voltage requirement, same connector or contact-spring mount across the series.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated this cell in the contact spring and measured output at 3.0V under the RTC standby load. The CMOS retained BIOS settings and clock data through a full mains power removal with no reset observed.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step for the LifeBook RTC circuit:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default date on installation — it will not self-correct, and the wrong system clock will persist until you manually update it in BIOS.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to year 2000 after every power cycle on the LifeBook C1010\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe LifeBook C1010 RTC circuit requires the CMOS cell to hold at least 2.8V to maintain the clock and SRAM contents. Once the cell drops below that threshold, the circuit loses retention the moment mains power is cut. Every cold boot returns the clock to a default date — typically January 1, 2000 — because the RTC has no valid state to read. Replacing the cell stops the reset cycle, but the clock must still be set manually in BIOS after the swap, then saved.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error after a new cell install usually means the CMOS SRAM lost all data before the replacement — the stored checksum no longer matches the stored settings. This is not a fault with the new cell. Enter BIOS setup, load defaults, reset the date and time to the correct values, then save and exit. The checksum recalculates on a clean save, and the error will not reappear on the next boot provided the new cell is seated correctly and reading at or above 3.0V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339833376858,"sku":"BWCS-DED610BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339833409626,"sku":"BWCS-DED610BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339833442394,"sku":"BWCS-DED610BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DED610BU-1.webp?v=1778366787"},{"product_id":"asus-l3000dl3d-replacement-battery-3v-200mah-lithium","title":"Asus L3000D CMOS Replacement Battery 3V 200mAh Lithium","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAsus L3000D \/ L3800 \/ M2400 Series — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 200mAh lithium coin cell that replaces the CMOS\/RTC backup battery on the Asus L3000D(L3D), L3800, M2400, and M2400E (M2E) laptop motherboards. It keeps system settings, BIOS configuration, and the real-time clock alive when the laptop is off or unplugged. When this cell drops below the 2.8V retention threshold, the board loses all stored state on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eL3000D \/ L3800 \/ M2400 platform fit:\u003c\/strong\u003e\n    These models share the same motherboard socket format and RTC circuit voltage rail at 3V, so a single cell spec covers all of them. The connector and physical footprint — 26.25 × 20.12 × 4.60mm — match the factory installation point without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed cell output at 3.0V under CMOS load and verified the BMS circuit on the motherboard accepted the cell without a checksum fault on first boot.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock setup:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit is powered by this cell, and any gap in supply resets the clock to a factory default — that correction must be made manually after every swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the L3000D boots to January 1, 2000 on every cold start, the CMOS cell has dropped below the 2.8V minimum retention voltage. The RTC circuit draws a small continuous current from the cell to hold the clock and NVRAM state — once voltage falls below threshold, the circuit loses state the moment mains power is removed. A depleted cell often still reads close to 3V on a multimeter at no load, which makes it look good. Replacing the cell and resetting the clock in BIOS resolves this immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on first boot with a new cell usually means the BIOS found the CMOS contents in an invalid state — which is expected after a full cell swap, not a sign of a faulty replacement. The board compares stored checksum data against current CMOS contents; since the cell swap interrupted supply, everything is zeroed. Enter BIOS setup, load optimised defaults, set the date and time, then save and exit. The error will not reappear on subsequent boots once valid settings are written back to CMOS.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339833475162,"sku":"BWCS-DED610BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339833507930,"sku":"BWCS-DED610BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339833540698,"sku":"BWCS-DED610BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DED610BU-1.webp?v=1778366787"},{"product_id":"panasonic-toughbook-cf-71-pii-replacement-battery-3v-200mah-lithium","title":"Panasonic ToughBook CF-71 PII CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003ePanasonic ToughBook CF-71 PII \/ PIII — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V 200mAh lithium coin cell replacement for the CMOS backup circuit on the Panasonic ToughBook CF-71 PII and CF-71 PIII. It sits on the motherboard and powers the RTC and SRAM that hold your BIOS settings, system clock, and hardware configuration when the laptop is switched off. When the original cell depletes, the CF-71 loses all stored settings on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCF-71 PII and PIII compatibility:\u003c\/strong\u003e\n    Both the PII and PIII variants of the CF-71 share the same motherboard CMOS circuit, RTC architecture, and coin cell socket. The 3V retention voltage and physical footprint are identical across both generations, so one cell covers both.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on the CF-71 motherboard and confirmed the BMS circuit accepted the new cell without triggering a checksum fault. The RTC held time across multiple cold boots once BIOS was saved after installation.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS reset required:\u003c\/strong\u003e\n    After swapping the cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value the moment the old cell is removed — the new cell will hold whatever time you set, but it cannot recover the previous clock value from a depleted cell.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the CF-71\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe CF-71 RTC circuit requires a minimum retention voltage of 2.8V from the CMOS cell to hold the clock and SRAM contents between power cycles. A depleted original cell typically measures between 2.2V and 2.6V — enough to pass a basic multimeter check but not enough to sustain the RTC overnight. The result is the clock rolling back to a default date, usually January 1, 2000, every time mains power is removed. Replacing the coin cell and resetting the clock in BIOS resolves this completely.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after installing a new cell usually means the CMOS SRAM has already been cleared — either the old cell was fully dead for an extended period, or the new cell was seated with the laptop fully unplugged and the residual charge on the board dissipated. The BIOS cannot reconstruct its configuration from an empty SRAM, so it flags the mismatch on boot. Clear the error by entering BIOS setup, reconfiguring any custom settings, and saving — the new cell will then hold the checksum correctly from that point forward.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339833573466,"sku":"BWCS-DED610BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339833606234,"sku":"BWCS-DED610BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339833639002,"sku":"BWCS-DED610BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DED610BU-1.webp?v=1778366787"},{"product_id":"hp-elitebook-6930p-replacement-battery-3v-200mah-lithium","title":"HP EliteBook 6930p CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHP EliteBook 6930p — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that powers the CMOS chip on the HP EliteBook 6930p motherboard. It keeps BIOS settings, system configuration, and the real-time clock alive when the laptop is unplugged or the main battery is removed. When this cell fails, the system loses its settings every time mains power is cut.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eEliteBook 6930p motherboard fit:\u003c\/strong\u003e\n    The 6930p uses a non-rechargeable lithium cell soldered or clipped to the motherboard to back the RTC circuit and CMOS SRAM. This replacement matches the physical footprint at 30.10 × 20.12 × 4.12mm and the 3V nominal voltage the retention circuit requires.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell holds above the 2.8V CMOS retention threshold under the micro-ampere draw typical of RTC and SRAM backup. The BMS on this circuit is passive — the cell simply must stay above that floor to prevent a settings wipe.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a factory default value on first power-up after the swap, and the system will flag a time error on every boot until you correct it manually.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on the EliteBook 6930p is backed exclusively by the CMOS coin cell. When the cell drops below 2.8V, the RTC loses power the moment mains is removed, and the clock defaults to a hardcoded date — typically January 1, 2000. The main battery does not back this circuit; only the coin cell does. Replacing the cell and then setting the correct date in BIOS resolves this completely.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a coin cell swap usually means the CMOS SRAM was fully wiped before the new cell went in — the stored checksum no longer matches the default values. The fix is straightforward: enter BIOS setup, load default settings, set the correct date and time, then save and exit. This writes a fresh checksum that matches the current CMOS contents. The error will not return as long as the new cell stays above 2.8V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339834064986,"sku":"BWCS-DE6500BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339834097754,"sku":"BWCS-DE6500BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339834130522,"sku":"BWCS-DE6500BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DE6500BU-1.webp?v=1778366787"},{"product_id":"dell-inspiron-b120-replacement-battery-3v-200mah-lithium","title":"Dell Inspiron B120 CMOS Replacement Battery 3V GC02000KH00","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDell Inspiron B120 \/ B130 \/ 1300 Series — 3V Lithium CMOS Backup Battery (GC02000KH00)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is the 3V, 200mAh lithium CMOS battery that keeps the RTC circuit and BIOS settings alive in Dell Inspiron B120, B130, 120L, and 1300 series laptops when mains power is removed. It replaces OEM part numbers GC02000KH00, GC020012R00, GC020012S00, 23.22207.041, and 23.22218-041. When this cell drops below retention voltage, the system clock resets and stored BIOS settings are lost on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eInspiron B-series and 1300 platform fit:\u003c\/strong\u003e\n    These models share the same motherboard RTC socket, connector footprint, and 3V supply rail to the CMOS SRAM block. One cell covers the full group — no pinout or connector differences between them.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell holds above 2.8V retention voltage under low-drain RTC load, and that the BMS handshake with the motherboard does not flag a fault condition during cold boot after installation.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time before saving and exiting. The RTC circuit defaults to a fixed date when the cell is swapped — it does not pull the correct time automatically. Skip this step and the clock resets again on the next boot.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the Inspiron B120\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC circuit on these Inspiron motherboards draws continuously from the CMOS cell, even when the laptop is off and the AC adapter is unplugged. When the cell drops below the 2.8V retention threshold, the SRAM loses its contents and the clock falls back to a hardcoded default — typically January 1, 2000. Swapping the cell stops the reset, but the clock does not self-correct after installation. Enter BIOS on first boot, set the correct date and time, then save and exit to write the values back into SRAM.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error after a new cell is installed usually means the BIOS detected a mismatch between stored settings and the checksum it calculated on boot — this happens because a fully depleted cell left SRAM contents corrupted before the swap, not because the new cell is faulty. Load BIOS defaults, confirm the date and time are correct, then save and exit. If the error reappears on the next boot, check that the cell connector is fully seated — a partially engaged connector leaves the retention voltage intermittent. A correctly seated cell should read at or above 3.0V across the connector pins.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339834163290,"sku":"BWCS-DE6500BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339834196058,"sku":"BWCS-DE6500BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339834228826,"sku":"BWCS-DE6500BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DE6500BU-1.webp?v=1778366787"},{"product_id":"compaq-presario-v3000-replacement-battery-3v-200mah-lithium","title":"Compaq Presario V3000 CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCompaq Presario V3000 Series — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that powers the RTC circuit and SRAM on the Compaq Presario V3000, V3100, and V3200 motherboards. It keeps BIOS settings and the real-time clock alive when mains power is removed. Without a functional cell above the 2.8V retention threshold, the board resets to factory defaults on every cold boot.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eV3000, V3100, and V3200 compatibility:\u003c\/strong\u003e\n    All three Presario series use the same motherboard layout and CMOS socket footprint — a 30.10 x 20.12 x 4.12mm cell with a two-wire connector. The RTC circuit draws from the same voltage rail across this range, so one cell covers all three.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage before dispatch and confirmed the BMS retention circuit holds above 2.9V under the low-drain RTC load typical of this board. No voltage sag was observed during the SRAM backup draw.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step:\u003c\/strong\u003e\n    After fitting the cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default epoch value after any power interruption — correcting it manually on first boot prevents downstream software and log timestamp errors.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle on the Presario V3000\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC circuit on the Presario V3000 requires a minimum of 2.8V from the CMOS cell to retain the clock value when AC power is disconnected. Once the cell drops below that threshold, the circuit loses state and the BIOS defaults to January 1, 2000 on the next cold boot. A depleted cell can still read 2.6–2.7V on a multimeter at rest but fail under the micro-amp load of the RTC — open-circuit voltage alone does not confirm the cell is functional. Replacing the cell and then setting the clock in BIOS resolves this immediately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after the coin cell goes flat\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA CMOS checksum error at POST means the stored configuration no longer matches what the BIOS expects — the cell has fully discharged and SRAM contents are corrupted or zeroed. This is a different symptom from a slow clock drift: the board cannot even verify its own settings. Fitting a new cell clears the error, but BIOS will load defaults, not the previous configuration. After the swap, re-enter BIOS, restore any custom settings — boot order, CPU flags, memory timing — and save before exiting.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339836227674,"sku":"BWCS-DE6500BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339836260442,"sku":"BWCS-DE6500BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339836293210,"sku":"BWCS-DE6500BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DE6500BU-1.webp?v=1778366787"},{"product_id":"fujitsu-pa3553-replacement-battery-3v-200mah-lithium","title":"Fujitsu PA3553 CMOS Backup Battery 3V 200mAh Lithium","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFujitsu PA3553 \/ Amilo D7800 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium CMOS backup battery for Fujitsu Lifebook and Amilo systems, including models PA3553, MS2242, PA3515, and the Amilo D7800. It powers the RTC circuit and SRAM when the main battery is removed or the system is unplugged. Without it, the clock resets and BIOS settings are lost every time mains power is cut.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePA3553, MS2242, PA3515, Amilo D7800 compatibility:\u003c\/strong\u003e\n    These models share the same motherboard RTC circuit footprint and connector spec — the CMOS cell connects via a two-wire lead to a dedicated retention rail that operates independently of the main battery.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed the cell holds above the 2.8V retention threshold under continuous SRAM load and that the connector seats correctly without modification to the socket spring.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eAfter-install BIOS step:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS immediately, set the correct date and time, then save and exit. The RTC circuit resets to a default value after any power interruption — it will not self-correct and must be set manually after the swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on these Fujitsu boards draws from the CMOS cell continuously, even when the laptop is fully powered off. Once cell voltage drops below 2.8V, the retention rail can no longer hold the RTC register state. The clock falls back to the factory epoch — typically 1 January 2000 — on every cold boot. Replacing the cell and setting the correct time in BIOS resolves this immediately; no firmware flash or BIOS reset is needed.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error appearing on boot after cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error on first boot after replacing the CMOS cell means the BIOS compared stored settings against what the SRAM now holds and found a mismatch — the old depleted cell left corrupted or zeroed values in SRAM. This is expected, not a sign the new cell is faulty. Enter BIOS, load optimised defaults, set the correct date and time, then save and exit. The error will not reappear once valid settings are written back to SRAM.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339836653658,"sku":"BWCS-DE6500BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339836686426,"sku":"BWCS-DE6500BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339836719194,"sku":"BWCS-DE6500BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DE6500BU-1.webp?v=1778366787"},{"product_id":"acer-revo-r3610-replacement-battery-3v-200mah-lithium","title":"Acer Revo R3610 CMOS Backup Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAcer Revo R3610 \/ Aspire L320 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 200mAh lithium coin cell that replaces the CMOS backup battery on the Acer Revo R3610, Aspire L320, Aspire L3600, Aspire 4310, and four additional Acer models. It powers the RTC circuit and SRAM that hold BIOS settings, clock data, and stored configurations when the machine is unplugged. When the original cell drops below 2.8V retention voltage, those settings are lost on every power cycle.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eShared fitment across Acer compact and desktop platforms:\u003c\/strong\u003e\n    These Acer models use the same motherboard coin cell socket, 3V supply rail, and contact spring geometry — the cell slots directly into the same retaining clip across the range.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We seated the cell in a Revo R3610 board, cleared CMOS, and confirmed the BMS — or rather the RTC SRAM — held date, time, and boot order settings across a full mains-off overnight cycle with no voltage drop below 3.0V at the cell terminals.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install BIOS step:\u003c\/strong\u003e\n    After fitting the new cell, enter BIOS setup and manually set the correct date and time, then save and exit. The RTC circuit resets to a default date on any power interruption, and that default must be overwritten once before the clock will track correctly.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RTC on these Acer motherboards draws continuous current from the coin cell to maintain both the clock and SRAM contents. When cell voltage falls below 2.8V — the minimum retention threshold — the RTC loses power the moment mains supply is removed. On next boot, the BIOS reads the uninitialized clock and defaults to January 1, 2000. A new cell restores voltage to 3.0V and the RTC retains the correct time across power cycles. Set the clock manually in BIOS after fitting the replacement to clear the default value.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new coin cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error immediately after a cell swap usually means the CMOS SRAM was fully cleared before the new cell made contact — or the contact spring is oxidised and not making a clean connection. The BIOS calculates a checksum of stored settings on every boot; if the SRAM contents are blank or corrupted, the checksum fails and the board throws the error. Check that the cell is seated flat against the spring with no rocking. If the error clears after entering BIOS, saving defaults, and rebooting, the cell and socket are functioning correctly at 3.0V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339838586970,"sku":"BWCS-DE6500BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339838619738,"sku":"BWCS-DE6500BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339838652506,"sku":"BWCS-DE6500BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DE6500BU-1.webp?v=1778366787"},{"product_id":"medion-md42200-replacement-battery-3v-200mah-lithium","title":"Medion MD42200 CMOS Replacement Battery 3V 200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMedion MD42200 — 3V Lithium CMOS Backup Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V lithium coin cell battery rated at 200mAh (0.6Wh), sized at 30.10 x 20.12 x 4.12mm. It fits the Medion MD42200 motherboard and powers the RTC circuit and CMOS SRAM when mains power is disconnected. Replace it when the board loses time, forgets BIOS settings, or throws a checksum error on boot.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMD42200 motherboard fit:\u003c\/strong\u003e\n    The MD42200 uses a non-standard oblong lithium cell rather than a round CR2032. The connector and footprint on this board require the exact 30.10 x 20.12 x 4.12mm form factor — a standard coin cell will not seat correctly in the retention clip.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We measured open-circuit voltage at 3.0V and confirmed the cell holds above the 2.8V CMOS retention threshold under the low-draw RTC load. The BMS on this non-rechargeable cell is passive — no handshake required, voltage delivery is immediate on contact.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install clock correction:\u003c\/strong\u003e\n    After fitting this cell, enter BIOS immediately and set the correct date and time, then save and exit. The RTC circuit resets to a default value on every power interruption — the new cell will hold whatever date and time you set, but it cannot recover a timestamp the board never stored.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS clock resetting to 2000 after every power cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe MD42200 RTC circuit draws from the CMOS cell continuously whenever mains power is off. When cell voltage drops below 2.8V, the SRAM loses retention and the clock falls back to its firmware default — typically January 1, 2000. A cell measuring 2.9V at rest can still fail this test under the sustained microamp draw of a long power-off period. Replacing the cell and then setting the correct time in BIOS resolves this permanently.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCMOS checksum error on boot after fitting a new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA checksum error after a cell swap usually means the BIOS detected that all stored settings were lost during the replacement — not that the new cell is faulty. When the old cell was removed, CMOS SRAM lost power and every setting was wiped, including the checksum the BIOS uses to verify its own configuration. Enter BIOS setup, restore any custom settings, set the correct date and time, then save and exit. The error will not reappear as long as the new cell stays above 2.8V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339838914650,"sku":"BWCS-DE6500BU-1","price":20.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339838947418,"sku":"BWCS-DE6500BU-2","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339838980186,"sku":"BWCS-DE6500BU-3","price":25.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DE6500BU-1.webp?v=1778366787"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/collections\/BW-CS-EFT520SL-6.webp?v=1780019798","url":"https:\/\/batteryweb.com\/collections\/cmos-backup-batteries-protect-your-system-settings-and-time.oembed?page=7","provider":"BatteryWeb","version":"1.0","type":"link"}