{"product_id":"advent-4211-replacement-battery-111v-4400mah-li-ion","title":"Advent 4211 Notebook Replacement Battery 11.1V 4400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAdvent 4211 \/ 4212 — 11.1V Li-ion Replacement Battery (BTY-S12)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is an 11.1V, 4400mAh (48.84Wh) lithium-ion battery that fits the Advent 4211 and 4212 notebook computers. It replaces OEM part BTY-S12 and restores unplugged operation when the original cell has degraded. Voltage and connector match the original specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e4211 and 4212 platform fit:\u003c\/strong\u003e\n    Both models share the same battery bay, connector pinout, and BMS communication protocol, which is why one cell covers both. The SMBus lines carry charge state and temperature data between the pack and the motherboard — the connector has to be exact for that handshake to work.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge and discharge cycles on a 4211 unit. The BMS negotiated correctly, charge current ramped through CC phase and tapered cleanly in CV, and the protection circuit tripped at the expected low-voltage cutoff without issue.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration tip:\u003c\/strong\u003e\n    After fitting this battery, run the laptop fully down until it hibernates on its own, then charge uninterrupted to 100% without using the machine. This gives the fuel gauge IC a full reference sweep against the new cell and clears the inaccurate health warning the BIOS displays 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\"\u003eBIOS reporting poor battery health immediately after fitting a new cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Advent 4211 stores battery health data in the EEPROM of the original pack. When a new cell goes in, the BIOS reads stale data from its own cached record and flags the battery as degraded before it has run a single cycle. This is not a fault with the replacement — it is a calibration state. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100%. After that cycle, the BIOS battery learn routine updates its reference and the health warning clears.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop cuts out at 20–30% charge shown on the gauge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC has not yet mapped the new cell's discharge curve. The gauge still references the old cell's voltage-to-capacity profile, so it misjudges where the voltage cliff sits. Under combined CPU and display load, the actual cell voltage drops below the BMS cutoff threshold before the gauge reaches 0%. The fix is two to three full calibration cycles — discharge to hibernate cutoff, charge to 100% — after which the IC recalibrates its model. If shutdown still occurs below 15% after three cycles, check that AC adapter output holds steady at 19V under load.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410826100826,"sku":"BWCS-MSU100HB-1","price":93.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43410826133594,"sku":"BWCS-MSU100HB-2","price":106.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43410826166362,"sku":"BWCS-MSU100HB-3","price":116.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MSU100HB-1.webp?v=1779581287","url":"https:\/\/batteryweb.com\/products\/advent-4211-replacement-battery-111v-4400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}