{"product_id":"lg-k8-replacement-battery-385v-2900mah-li-polymer","title":"BL-O1 LG K8+ Replacement Battery 3.85V 2900mAh Li-Polymer","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eLG K8+ \/ X120 Nova \/ K20 2019 — 3.85V Li-Polymer Replacement Battery (BL-O1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 2900mAh Li-Polymer replacement battery for the LG K8+, K8 Plus, X120 Nova, and K20 2019. It carries OEM part numbers BL-O1, EAC64559001, and EAC64619301. It fits directly into these models and restores full device operation when the original cell has degraded or failed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eK8+ \/ X120 \/ K20 2019 platform fit:\u003c\/strong\u003e\n    These models share the same 3.85V single-cell architecture, BL-O1 connector pinout, and BMS handshake protocol. One cell covers the full variant list without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell on a K8+ unit and monitored BMS communication throughout charge and discharge. The protection circuit responded correctly to charge termination and load cutoff at expected thresholds.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installation, run one full discharge down to automatic shutdown, then charge uninterrupted to 100% before enabling fast charge. This gives the fuel gauge IC a clean discharge curve to reference against the new cell — skipping this step is the primary cause of erratic percentage readings in the first week.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the LG K8+ after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe K8+ fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, the stored curve no longer matches the actual voltage-versus-capacity profile of the replacement. Under modem transmission or screen-on load, the phone draws a current spike that drops cell voltage below the OS cutoff threshold — even though the coulomb counter still shows charge remaining. The fix is one full uninterrupted discharge-to-shutdown cycle followed by a full charge. After that single cycle, the fuel gauge IC recalibrates and shutdown behaviour normalises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eFast charge not activating on the first cycle after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe K8+ charge IC negotiates fast charge parameters with the BMS on every boot. On a freshly installed cell with no cycle history, the BMS presents high internal impedance and the charge IC defaults to standard 5V\/1A to protect the cell. This is expected behaviour, not a fault. Complete one full standard charge cycle and the impedance drops enough for the charge IC to re-enter fast charge negotiation. If fast charge still does not activate after two full cycles, check that the charger output matches the required protocol for this handset.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391894945882,"sku":"BWCS-LPX120SL-1","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391894978650,"sku":"BWCS-LPX120SL-2","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391895011418,"sku":"BWCS-LPX120SL-3","price":31.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LPX120SL-1.webp?v=1779142596","url":"https:\/\/batteryweb.com\/products\/lg-k8-replacement-battery-385v-2900mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}