{"product_id":"oppo-realme-1-replacement-battery-385v-3350mah-li-polymer","title":"Oppo Realme 1 BLP665 Replacement Battery 3.85V 3350mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eOppo Realme 1 \/ F7 Youth — 3.85V Li-Polymer Replacement Battery (BLP665)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3350mAh, 3.85V lithium-polymer cell carrying OEM part number BLP665. It fits the Realme 1 (CPH1861, CPH1859) and the F7 Youth — all variants that share the same battery bay dimensions and connector. Use the product data capacity figure: 3350mAh \/ 12.9Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCPH1861, CPH1859, and F7 Youth compatibility:\u003c\/strong\u003e\n    These models run the same 3.85V power rail, use an identical flex connector, and share the same BMS handshake protocol — which is why one cell covers all three. Swapping between these variants requires no wiring 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 CPH1861 unit and monitored BMS charge-termination voltage. The protection circuit cut charge at 4.35V and triggered low-voltage cutoff at 3.0V — both within spec for this platform.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration after swap:\u003c\/strong\u003e\n    On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated coulomb counter.\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 BLP665 replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a voltage cliff issue, not a capacity defect. When the modem fires a transmission burst or the screen jumps to full brightness, instantaneous current draw spikes. If the fuel gauge IC is still calibrated to the old cell's discharge curve, it misreads state-of-charge at high-load moments. The cell voltage sags below the BMS cutoff threshold even though the reported percentage looks safe. One full discharge-charge cycle with fast charging off resets the coulomb counter and eliminates most of these shutdowns.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone reports wrong battery percentage after cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Realme 1's fuel gauge IC stores an internal model of the old cell's impedance and voltage-to-capacity curve. After fitting a new BLP665, those stored values no longer match the fresh cell's characteristics, so the percentage reading drifts — often showing 100% prematurely or dropping suddenly. Drain the battery to automatic shutdown, then charge uninterrupted to 100% with fast charging disabled. After that single cycle the coulomb counter resets to the new cell's actual curve and percentage accuracy stabilises.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392008749146,"sku":"BWCS-OPR186SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392008781914,"sku":"BWCS-OPR186SL-2","price":29.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392008814682,"sku":"BWCS-OPR186SL-3","price":32.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-OPR186SL-1.webp?v=1779142904","url":"https:\/\/batteryweb.com\/products\/oppo-realme-1-replacement-battery-385v-3350mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}