{"product_id":"xiaomi-mi-cc9e-replacement-battery-385v-3950mah-li-polymer","title":"Xiaomi Mi CC9e BM4F Replacement Battery 3.85V 3950mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eXiaomi Mi CC9e — 3.85V Li-Polymer Replacement Battery (BM4F)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3950mAh Li-Polymer cell built to the BM4F specification for the Xiaomi Mi CC9e and its regional variants. It fits the Mi CC9e Standard Edition, the Dual SIM variant, and the M1906F9SC — all of which share the same battery bay and connector pinout. Voltage is 3.85V nominal; full pack energy is 15.21Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMi CC9e variant coverage:\u003c\/strong\u003e\n    The Standard Edition, Standard Edition Dual SIM, and M1906F9SC all use the same BM4F footprint — same connector, same BMS handshake, same charge IC protocol. One cell covers the full regional lineup.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge and discharge cycles on a CC9e unit. The BMS accepted the charge IC handshake cleanly, protection circuits tripped correctly at low-voltage cutoff, and the fuel gauge IC tracked state-of-charge without error flags after the first full cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge reset:\u003c\/strong\u003e\n    After installation, disable fast charging and run one complete discharge down to auto-shutdown, then charge to 100% on standard 5V. This lets the coulomb counter recalibrate its discharge curve against the new cell before high-current fast charging begins pushing variable current into an uncalibrated gauge.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the CC9e reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe CC9e uses a fuel gauge IC that builds its state-of-charge model against the discharge curve of the original cell. When a new cell goes in, that stored curve no longer matches actual cell chemistry, so the reported percentage drifts — often reading 30% when the phone is close to shutdown. The gauge needs a full reference cycle to relearn the new cell's voltage-to-capacity relationship. One slow discharge to cutoff followed by a full charge resolves it. After that cycle, percentage reporting stabilises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the cell voltage drops below the modem or display load threshold before the fuel gauge has recalibrated. The phone sees 25% on the gauge but the actual cell voltage collapses under peak draw — the BMS trips protection and the phone cuts off. It is not a faulty cell; it is an uncalibrated coulomb counter. Run the first-cycle reset: discharge fully to auto-shutdown, then charge uninterrupted to 100% at standard 5V. After one complete reference cycle, the gauge tracks actual cell voltage and shutdowns at low percentage stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392001638490,"sku":"BWCS-MUC900SL-1","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392001671258,"sku":"BWCS-MUC900SL-2","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392001704026,"sku":"BWCS-MUC900SL-3","price":31.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MUC900SL-1.webp?v=1779142855","url":"https:\/\/batteryweb.com\/products\/xiaomi-mi-cc9e-replacement-battery-385v-3950mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}