{"product_id":"sager-np8258-replacement-battery-148v-5200mah-li-ion","title":"Sager NP8258 Replacement Battery 14.8V 5200mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSager NP8258 \/ NP8250 — 14.8V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 14.8V, 5200mAh (76.96Wh) lithium-ion battery for the Sager NP8258 and NP8250 laptops. It slots into the original battery bay and connects to the same charge controller used by the factory cell. Voltage and connector pinout match both models in this series.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNP8258 and NP8250 compatibility:\u003c\/strong\u003e\n    Both notebooks share the same 14.8V battery rail, bay dimensions, and BMS handshake protocol — one cell covers both. The charge controller in each model negotiates with the same EEPROM signature, so no firmware conflict occurs at install.\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 load discharge on a 14.8V notebook platform. The BMS reported correct voltage at each stage and held the charge cutoff within spec. No false low-battery flags triggered during the test run.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle reset on the NP8258:\u003c\/strong\u003e\n    After installing, run one full discharge to the hibernate cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell data 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\"\u003eBIOS reporting poor battery health immediately after swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe NP8258 BIOS reads health data stored in the old cell's EEPROM and caches it. When a new cell goes in, that stale data doesn't clear automatically — the system still displays the previous cell's degraded health rating. This is a firmware cache issue, not a fault with the replacement cell. One full discharge-to-hibernate followed by an uninterrupted charge to 100% triggers the battery learn cycle and rewrites the cached values against the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop shuts down at 20–30% charge shown on screen\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC hasn't calibrated against the new cell yet. The displayed percentage drifts from actual remaining capacity, so the laptop hits a voltage cliff under full CPU and display load before the gauge reaches zero. The cell's voltage drops below the BMS cutoff threshold while the OS still shows charge remaining. Run two to three full discharge-to-100% cycles and the fuel gauge IC will recalibrate — shutdowns should stop occurring above 10% after that.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409558503514,"sku":"BWCS-CLP157NB-1","price":98.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409558536282,"sku":"BWCS-CLP157NB-2","price":116.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409558569050,"sku":"BWCS-CLP157NB-3","price":129.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CLP157NB-1.webp?v=1779580013","url":"https:\/\/batteryweb.com\/products\/sager-np8258-replacement-battery-148v-5200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}