{"product_id":"advent-a440-replacement-battery-148v-4400mah-li-ion","title":"Advent A440 Laptop Replacement Battery 14.8V 4400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAdvent A440 — 14.8V Li-ion Replacement Battery (A44)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 14.8V, 4400mAh (65.12Wh) Li-ion replacement battery for the Advent A440 laptop. It replaces the original cell when the existing battery no longer holds charge or fails to power the machine. OEM part numbers covered include A44, 21-91026-50, and the full 21-91083 and 21-92079 variant series.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eA440 cell fitment:\u003c\/strong\u003e\n    The A440 uses a 14.8V four-cell series configuration. All OEM part variants in this listing share the same voltage rail, connector pinout, and BMS handshake protocol — so the same replacement cell covers the full range.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge and discharge on a live A440 board. The BMS negotiated correctly, charge current ramped to CC phase without fault codes, and the protection circuit tripped cleanly at low-voltage cutoff.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle calibration on the A440:\u003c\/strong\u003e\n    After fitting, run the laptop on battery until it hibernates at low charge, then charge uninterrupted to 100% without unplugging. This forces the BIOS battery learn cycle to complete against the new cell and clears the inaccurate health warning that appears after every cell swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop shutting down at 20–30% remaining after battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the fuel gauge IC still holds calibration data from the old degraded cell. Under full CPU and display load, the new cell's actual voltage curve doesn't match the stored data, so the laptop hits a voltage cliff it wasn't expecting. The system shuts down to protect itself even though remaining capacity exists. Run two full discharge-to-hibernate then uninterrupted charge cycles — the fuel gauge IC recalibrates against the new cell's voltage curve and the shutdowns stop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS reporting battery health as poor immediately after fitting\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe BIOS reads health state from EEPROM data written by the previous cell's charge cycles — not from the new cell's actual chemistry. A fresh cell registers as degraded because cycle count and capacity data from the old unit are still in memory. This is not a fault with the replacement. Complete one full learn cycle — discharge to hibernate cutoff, then charge uninterrupted to 100% — and the BIOS health status resets to normal.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410825576538,"sku":"BWCS-ADA440NB-1","price":82.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43410825609306,"sku":"BWCS-ADA440NB-2","price":97.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43410825642074,"sku":"BWCS-ADA440NB-3","price":107.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ADA440NB-1.webp?v=1779581286","url":"https:\/\/batteryweb.com\/products\/advent-a440-replacement-battery-148v-4400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}