{"product_id":"sager-np8451pb51rc-replacement-battery-111v-5400mah-li-ion","title":"Sager NP8451 11.1V Replacement Battery 5400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSager NP8451(PB51RC) Series — 11.1V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is an 11.1V Li-ion replacement battery rated at 5400mAh (59.94Wh) for the Sager NP8451(PB51RC) and related notebooks. It fits multiple Sager models including the NP8454(PB51RF), NP8377-S(PB71RF-G), and NP8356(PB51EF-G). It slots into the same bay as the original and connects to the same charging circuit.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNP8451 and PB51RC platform compatibility:\u003c\/strong\u003e\n    These Sager models share a common 11.1V three-cell battery bay, identical connector pinout, and the same BMS handshake protocol — which is why a single cell works across all four listed models without firmware conflicts.\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 full discharge on an NP8451-class board. The BMS accepted the new cell without a reject flag, and the protection circuit tripped correctly at the low-voltage cutoff threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration cycle:\u003c\/strong\u003e\n    After fitting this battery, run the laptop down to hibernate cutoff without interruption, then charge uninterrupted to 100%. This forces the BIOS to relearn cell capacity against fresh chemistry 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\"\u003eWhy the BIOS flags poor battery health immediately after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eSager notebooks store battery wear data in EEPROM on the old cell's BMS board. When a new cell is installed, the BIOS reads no accumulated charge history and interprets that as a degraded or unknown battery. This is not a fault with the replacement cell. Running one complete discharge-to-hibernate followed by a full uninterrupted charge writes fresh baseline data to the new cell's EEPROM. After two to three cycles, the health status typically resolves to normal.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop shuts down hard at 20–30% charge remaining\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC has not yet calibrated against the new cell's actual voltage curve. The OS reads a stale curve, reports 20–30% remaining, but the cell's real voltage has already dropped below what the CPU and display draw can sustain. The result is a hard shutdown with no warning. Run two full discharge-to-hibernate cycles without interruption — this lets the fuel gauge IC map the actual low-voltage cliff of the new cell. After calibration, the gauge cutoff should align with a cell voltage near 9.0V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409541169242,"sku":"BWCS-CLH571NB-1","price":88.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409541202010,"sku":"BWCS-CLH571NB-2","price":104.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409541234778,"sku":"BWCS-CLH571NB-3","price":115.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CLH571NB-1.webp?v=1779579964","url":"https:\/\/batteryweb.com\/products\/sager-np8451pb51rc-replacement-battery-111v-5400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}