{"product_id":"blackberry-keyone-replacement-battery-385v-3400mah-li-polymer","title":"BlackBerry KEYone BAT63108-003 Replacement Battery 3.85V 3400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBlackBerry KEYone — 3.85V Li-Polymer Replacement Battery (BAT63108-003)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3400mAh (13.09Wh) 3.85V lithium-polymer replacement battery for the BlackBerry KEYone and Mercury smartphones. It replaces the original BAT63108-003 cell and fits BBB100-1 and related KEYone variants. Dimensions are 80.80 × 50.76 × 5.00mm — confirm these against your existing cell before installation.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eKEYone and Mercury compatibility:\u003c\/strong\u003e\n    Both devices share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The KEYone (BBB100-1 and TD-LTE variants) uses the same charge IC communication lines as the Mercury, so one cell 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 ran this cell on a KEYone BBB100-1 unit. The BMS accepted the charge handshake immediately, and the fuel gauge IC began tracking state-of-charge within the first partial cycle. No charge rejection or error flags appeared during testing.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fast charging on a new cell:\u003c\/strong\u003e\n    On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before the charge IC pushes high current into an uncalibrated cell — reducing the risk of inaccurate percentage readings early on.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the KEYone after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA new cell has a different internal resistance curve than the degraded cell the fuel gauge IC was calibrated to. When the modem fires up during a call or data burst, current draw spikes and voltage drops faster than the gauge predicts. The phone interprets this as a hard undervoltage event and shuts down, even though the displayed percentage still shows capacity remaining. One full discharge-to-shutdown followed by a complete charge cycle resets the coulomb counter and aligns the gauge to the new cell's actual voltage cliff — typically around 3.4–3.5V under load.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB-PD fast charge not negotiating on the first cycle after replacement\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eAfter a cell swap, the KEYone's charge IC sometimes defaults to standard 5V charging on the first connection while the BMS completes its initialisation sequence. This is not a fault with the charger or the new cell. Disconnect the cable, wait 10 seconds, and reconnect — the PD negotiation handshake retries and the fast charge protocol typically resumes. If it persists past the first full cycle, check that the USB-C port is clean and the cable supports USB-PD at the rated amperage.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392051118170,"sku":"BWCS-BRK100SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392051150938,"sku":"BWCS-BRK100SL-2","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392051183706,"sku":"BWCS-BRK100SL-3","price":33.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BRK100SL-1.webp?v=1779143470","url":"https:\/\/batteryweb.com\/products\/blackberry-keyone-replacement-battery-385v-3400mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}