{"product_id":"redmi-k50-pro-replacement-battery-387v-4850mah-li-polymer","title":"Redmi K50 Pro BM5E Replacement Battery 3.87V 4850mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eRedmi K50 Pro — 3.87V Li-Polymer Replacement Battery (BM5E)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThe BM5E is the OEM-matched Li-Polymer cell for the Redmi K50 Pro (22021211RC \/ 22011211C). It runs at 3.87V nominal with a 4850mAh \/ 18.77Wh capacity. This replaces a degraded or failed original cell in the K50 Pro chassis.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eK50 Pro model variants (22021211RC, 22011211C):\u003c\/strong\u003e\n    Both model codes share the same BM5E connector pinout, cell dimensions, and BMS handshake — the fuel gauge IC and charge controller are identical across the variant line, so one cell fits all.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran the BM5E through a full charge and discharge cycle on the K50 Pro, confirmed BMS communication over the battery connector, and verified the charge IC accepted the cell without throwing a fault flag.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration after install:\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 its coulomb counter against the new cell's discharge curve before high-current charging is applied to an uncalibrated cell.\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 BM5E replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a voltage cliff issue, not a cell defect. The K50 Pro's modem and display pull high current spikes that drop cell voltage below the BMS cutoff threshold before the fuel gauge reads zero. It happens most often when the fuel gauge IC is still calibrated to the old, degraded cell curve. Run one full discharge to automatic shutdown, then charge uninterrupted to 100% — after that cycle the fuel gauge re-anchors its empty and full endpoints to the new cell and the early shutdowns stop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB-PD fast charge rejected on first cycle after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAfter a cell swap, the charge IC on the K50 Pro sometimes defaults to standard 5V charging until the BMS completes one handshake cycle with the new cell. The proprietary fast-charge protocol — which negotiates voltage up to 11V — waits for BMS confirmation before stepping up. Plug into the original Redmi charger, allow the first full charge to complete at whatever rate the phone accepts, and fast charge will re-engage on subsequent cycles. If it still does not step up after two full cycles, check that the battery connector is fully seated — a partially seated pin breaks the BMS data line.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391843500122,"sku":"BWCS-MUK520SL-1","price":38.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391843532890,"sku":"BWCS-MUK520SL-2","price":44.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391843565658,"sku":"BWCS-MUK520SL-3","price":48.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MUK520SL-1.webp?v=1779142367","url":"https:\/\/batteryweb.com\/products\/redmi-k50-pro-replacement-battery-387v-4850mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}