{"product_id":"xiaomi-redmi-k30-replacement-battery-385v-4400mah-li-polymer","title":"Xiaomi Redmi K30 BM4P Replacement Battery 3.85V 4400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eXiaomi Redmi K30 \/ K30 5G — 3.85V Li-Polymer Replacement Battery (BM4P)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThe BM4P is the OEM-referenced Li-Polymer cell for the Xiaomi Redmi K30 and Redmi K30 5G smartphones (M2001G7AE, M2001G7AC). It runs at 3.85V nominal and delivers 4400mAh (16.94Wh). This replacement restores the original power capacity when the factory cell has aged beyond useful service.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eK30 and K30 5G platform fit:\u003c\/strong\u003e\n    Both variants share the same battery bay dimensions (86.30 × 64.50 × 4.25mm), the same BM4P part number, and the same BMS handshake protocol — one cell covers both boards without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled the BM4P through charge and discharge on K30 hardware. The BMS accepted the cell without fault codes, and the charge IC applied the correct taper current at the top-of-charge threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installation, disable fast charging and run one full discharge-charge cycle at standard current. The fuel gauge IC recalibrates its coulomb counter against the new cell's discharge curve — skipping this step causes percentage errors on early cycles.\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 a freshly installed BM4P\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. The K30 reads apparent charge remaining from a coulomb counter trained on a degraded cell — the new cell hits a steeper voltage drop under modem or display load than the IC expects, and the system shuts down before the counter reaches zero. It is not a fault with the replacement cell. Run one complete discharge to auto-off, then charge to 100% without interruption. After that cycle the percentage reporting stabilises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB-PD or proprietary fast charge not triggering after cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eOn the first charge after installation, the charge IC sometimes falls back to 5V standard charging and will not negotiate the higher voltage profile. This occurs because the BMS has not yet confirmed cell state to the charge controller. Plug in with the original Xiaomi charger, let the first cycle complete fully at whatever current it accepts, then unplug and reconnect. The fast-charge handshake typically re-engages from the second charge onward once the BMS has a valid state-of-charge reading above 3.7V per cell.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391946784858,"sku":"BWCS-MUK300SL-1","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391946817626,"sku":"BWCS-MUK300SL-2","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391946850394,"sku":"BWCS-MUK300SL-3","price":35.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MUK300SL-1.webp?v=1779142720","url":"https:\/\/batteryweb.com\/products\/xiaomi-redmi-k30-replacement-battery-385v-4400mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}