{"product_id":"hp-420-replacement-battery-108v-6600mah-li-ion","title":"HP ProBook 420 G1 Compatible Battery 10.8V 6600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHP ProBook 420 \/ 620 Series — 10.8V Li-ion Replacement Battery (HSTNN-IB1A)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 10.8V, 6600mAh (71.28Wh) lithium-ion battery for the HP 420, 425, 4320t, and 620 notebook series. It replaces OEM parts including HSTNN-IB1A, HSTNN-CB1A, 587706-751, and 593572-001, among others. Fits the original battery bay and connector without modification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e420 \/ 425 \/ 620 platform fit:\u003c\/strong\u003e\n    These models share the same 10.8V battery rail, identical connector housing, and compatible BMS handshake. One cell works across the whole family because HP used a common power architecture across this generation of business notebooks.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell on a 420 unit and confirmed the BMS communicated correctly with the BIOS — charge accepted, fuel gauge registered, and no unknown device flag appeared at the power settings screen.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle discharge procedure:\u003c\/strong\u003e\n    After installing, run the laptop on battery until it reaches hibernate cutoff — do not interrupt mid-cycle. Then charge uninterrupted to 100%. This triggers the BIOS battery learn cycle and resets the health register that often shows a false warning 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\"\u003eHP's BIOS reads health data from the battery's EEPROM on first contact. When a new cell arrives, the EEPROM registers do not match the charge history the BIOS expected from the old cell. This triggers a \"calibrate battery\" or \"poor health\" flag — not a fault with the new cell. Run one full discharge-to-hibernate, then a full uninterrupted charge. After that cycle, the BIOS learn routine re-writes its health baseline against the new cell's actual capacity data.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop shuts down at 20–30% charge shown on the OS fuel gauge\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 chemistry. The IC is still using lookup tables built from the old, degraded cell — so it misreads the voltage curve and declares empty too early. The fix is two to three full discharge-and-charge calibration cycles. After those cycles, the OS gauge tracks the actual cell voltage and the early shutdowns stop. If it persists beyond three cycles, check that the BIOS charge threshold setting is not capped — navigate to HP Battery Health Manager under BIOS setup (F10) and confirm it is set to \"Maximize my battery health\" or \"Let HP manage.\"\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409814192218,"sku":"BWCS-HPF420HB-1","price":109.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409814224986,"sku":"BWCS-HPF420HB-2","price":124.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409814257754,"sku":"BWCS-HPF420HB-3","price":136.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HPF420HB-1.webp?v=1779581043","url":"https:\/\/batteryweb.com\/products\/hp-420-replacement-battery-108v-6600mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}