{"product_id":"hp-420-replacement-battery-108v-4400mah-li-ion","title":"HP ProBook 420 Replacement Battery 10.8V 4400mAh 587706-751","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHP ProBook 420 \/ 620 Series — 10.8V Li-ion Replacement Battery (587706-751)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 10.8V, 4400mAh (47.52Wh) Li-ion battery for the HP ProBook 420, 425, 4320t, 620, and related models. It replaces OEM part numbers including 587706-751, HSTNN-IB1A, HSTNN-CB1A, and HSTNN-LB1A. If your original cell no longer holds a charge or your notebook loses power off AC, this is the direct swap.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eProBook 420 \/ 425 \/ 4320t \/ 620 compatibility:\u003c\/strong\u003e\n    These models share the same battery bay geometry, connector pinout, and BMS communication protocol. One cell fits all of them — no adapter or firmware workaround needed.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through full charge and discharge cycles on ProBook 420 hardware. The BMS authenticated correctly, reported accurate state-of-charge to the OS, and held voltage within spec across the discharge curve.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration tip:\u003c\/strong\u003e\n    After fitting this cell, run the notebook on battery until it hibernates at low charge, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after almost every cell replacement 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\"\u003eBIOS reporting battery health as poor immediately after fitting a new cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe HP ProBook BIOS reads health data from EEPROM fields written by the original factory cell. A replacement cell ships with different EEPROM baseline values, so the BIOS flags it as degraded even when the cell is new. This is a data mismatch, not a fault with the battery. Running one full discharge-to-hibernate followed by a full uninterrupted charge lets the system rewrite its fuel gauge baseline against the new cell's actual chemistry. After one or two cycles, the health warning clears.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNotebook shuts down abruptly while showing 20–25% remaining\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the cell voltage drops below the BMS cutoff threshold under combined CPU and display load before the fuel gauge reaches zero. The fuel gauge IC is still reading the old cell's discharge curve, so the percentage shown is wrong. The cell hits a voltage cliff — typically around 9.9V under load — and the BMS trips before the OS-reported percentage catches up. Run two full calibration cycles and the fuel gauge IC will remap its curve to the new cell's actual discharge profile.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410806276186,"sku":"BWCS-HPF420NB-1","price":105.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43410806308954,"sku":"BWCS-HPF420NB-2","price":121.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43410806341722,"sku":"BWCS-HPF420NB-3","price":131.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HPF420NB-1.webp?v=1779581158","url":"https:\/\/batteryweb.com\/products\/hp-420-replacement-battery-108v-4400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}