{"product_id":"oppo-a1k-replacement-battery-385v-4000mah-li-polymer","title":"Oppo A1K BLP711 Replacement Battery 3.85V 4000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eOppo A1K \/ CPH1923 — 3.85V Li-Polymer Replacement Battery (BLP711)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 4000mAh Li-Polymer replacement battery for the Oppo A1K smartphone (CPH1923). It replaces the original BLP711 cell and restores power to the display, processor, and wireless radios. Dimensions are 87.35 × 60.20 × 4.00mm — confirm your existing cell before ordering.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eA1K \/ CPH1923 platform fit:\u003c\/strong\u003e\n    The A1K and CPH1923 are the same hardware variant sold across different regions. Both use the BLP711 cell on a shared voltage rail with the same connector orientation and BMS handshake — no adapter or modification 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 the A1K board. The BMS accepted charge handoff without error flags, and protection circuits tripped correctly at the expected low-voltage cutoff threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After fitting this cell, disable VOOC fast charging for the first complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve accurately before high-current charging pushes current 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\"\u003eWhy the Oppo A1K shuts down suddenly at 20–30% after a battery swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe A1K's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, the old curve no longer matches the actual voltage profile of the replacement. Under modem or screen load, the phone reads 25% but the cell voltage has already dropped below the safe floor — the BMS cuts power before the OS can log a low-battery event. One full discharge-to-shutdown followed by a full charge resets the coulomb counter and resolves the mismatch. After that cycle, percentage readings stabilise.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eVOOC fast charge not activating on the first cycle after fitting\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eOppo's VOOC protocol negotiates with the battery's BMS before switching to high-current charge mode. On the first cycle with a new cell, the charge IC runs a standard 5V\/1A handshake while it verifies BMS parameters — VOOC will not engage until this check passes. The phone may show a slow-charge icon even with a VOOC adapter plugged in. Let the first full charge complete at standard rate; VOOC activates normally from the second cycle onward once the charge IC has logged a valid BMS response.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391993020506,"sku":"BWCS-OPH192SL-1","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391993053274,"sku":"BWCS-OPH192SL-2","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391993086042,"sku":"BWCS-OPH192SL-3","price":31.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-OPH192SL-1.webp?v=1779142762","url":"https:\/\/batteryweb.com\/products\/oppo-a1k-replacement-battery-385v-4000mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}