{"product_id":"fujitsu-lifebook-b2620-replacement-battery-108v-4400mah-li-ion","title":"Fujitsu LifeBook B2620 Replacement Battery 10.8V 4400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFujitsu LifeBook B2620 — 10.8V Li-ion Replacement Battery (FMVNBP109)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 10.8V, 4400mAh (47.52Wh) lithium-ion battery replaces the original cell in the Fujitsu LifeBook B2620 and closely related B-series notebooks. It also fits the LifeBook B2566, B2545, and B2175A, among others. OEM part numbers FMVNBP109, FMVNBP108, FPCBP36, and FPCBP37 all cross to this cell.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eB-series voltage rail compatibility:\u003c\/strong\u003e\n    The LifeBook B2620 and its siblings in the B2000 and B2100 family share the same 10.8V three-cell architecture and identical connector pinout. The BMS handshake protocol is consistent across all listed models, so a single cell design covers the full compatibility range without any firmware or hardware variation.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through full charge and discharge on a LifeBook B-series unit and confirmed the BMS negotiated correctly with the system board. Charge termination fired at the expected cutoff voltage with no false trips or safety-flag errors reported in the system log.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration for the B2620:\u003c\/strong\u003e\n    After fitting this cell, run the laptop down to hibernate-level cutoff on battery alone — with the display at full brightness and a background task running — then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate \"poor health\" warning that commonly appears after any cell swap on this platform.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the LifeBook B2620 shuts down at 20–30% after a battery swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe B2620's BIOS tracks discharge curves from the previous cell and maps its shutdown threshold against that stored data. When a new cell is installed, the voltage-versus-capacity curve no longer matches what the firmware expects, so it triggers a low-battery shutdown while the cell still has usable charge. This is a calibration mismatch, not a cell fault. Running one full uninterrupted discharge-to-hibernate followed by a full charge corrects the curve mapping. After two or three cycles the gauge stabilises and premature shutdowns stop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS reports battery Wh as incorrect after fitting a replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Wh figure shown in the BIOS or OS comes from EEPROM data embedded in the battery's BMS board, not from a live measurement. Some replacement cells carry EEPROM values that reflect the rated chemistry specification rather than the exact capacity of the installed cell, so the system may display a Wh figure that differs from the label. This is a data field discrepancy and does not affect actual charge delivery. To verify real capacity, run a full discharge cycle and compare the energy drawn against the nominal 47.52Wh figure — within 5% is normal for a new cell.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410846253146,"sku":"BWCS-FUB2620NB-1","price":68.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43410846285914,"sku":"BWCS-FUB2620NB-2","price":81.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43410846318682,"sku":"BWCS-FUB2620NB-3","price":90.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FUB2620NB-big.webp?v=1779581320","url":"https:\/\/batteryweb.com\/products\/fujitsu-lifebook-b2620-replacement-battery-108v-4400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}