{"product_id":"lenovo-serveraid-8s-pcie-replacement-battery-37v-1800mah-li-ion","title":"Lenovo ServeRaid-8s PCIe 39R8812 Compatible Battery 3.7V 1800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLenovo ServeRaid-8s PCIe — 3.7V Li-ion Replacement Battery (39R8812)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V 1800mAh Li-ion cell replaces the OEM battery on the Lenovo ServeRaid-8s PCIe RAID controller. It provides backup power to the controller's cache memory during unexpected power loss, protecting buffered write data until the system recovers. Voltage and capacity match the 39R8812 \/ 25R8118 OEM specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eServeRaid-8s PCIe compatibility:\u003c\/strong\u003e\n    The 8s PCIe controller uses a dedicated BBU slot tied to a specific voltage rail and BMS handshake. This cell meets that voltage threshold, so the controller recognises the unit and transitions its BBU status correctly.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge, rest, and discharge on a BBU load fixture. The BMS accepted the cell without throwing a fault code, and charge termination occurred at the expected voltage ceiling.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eLearn cycle initiation after swap:\u003c\/strong\u003e\n    After fitting this battery, trigger a BBU learn cycle from your management interface — StorCLI: \u003ccode\u003e\/cx bbu show\u003c\/code\u003e and then initiate recalibration. The controller holds write-through mode until the learn cycle completes and recalculates the backup window against the new cell's actual capacity.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eRAID controller staying in write-through mode after battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ServeRaid-8s PCIe does not automatically switch to write-back mode when a new battery is installed. It waits for the BBU learn cycle to complete and confirm the cell can sustain the backup window threshold. Until that cycle runs, the controller treats the battery as uncalibrated and keeps caching disabled. On Broadcom\/LSI-based controllers, run \u003ccode\u003eStorCLI \/c0 bbu startlearning\u003c\/code\u003e to kick off the process — it typically takes 24 to 72 hours under normal server load.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eManagement console showing a battery fault days after installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ServeRaid-8s PCIe runs its battery self-assessment on a timed schedule, not at boot. If the console flags a battery error two or three days after the swap, the scheduled assessment ran before the learn cycle had finished recalibrating the new cell. This is not a fault with the replacement cell itself. Let the learn cycle complete fully, then check the BBU status again — a healthy cell reads above 3.6V at rest with charge status showing \"Optimal\" in the controller log.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416094343258,"sku":"BWCS-ABM600SL-1","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416094376026,"sku":"BWCS-ABM600SL-2","price":31.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416094408794,"sku":"BWCS-ABM600SL-3","price":34.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ABM600SL-1.webp?v=1779760263","url":"https:\/\/batteryweb.com\/products\/lenovo-serveraid-8s-pcie-replacement-battery-37v-1800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}