{"product_id":"xiaomi-2409brn2ca-replacement-battery-384v-4750mah-li-polymer","title":"Xiaomi Redmi Note 9 Pro BN5X Compatible Battery 3.84V 4750mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eXiaomi Redmi Note 9 Pro — 3.84V Li-Polymer Replacement Battery (BN5X)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.84V, 4750mAh (18.24Wh) lithium-polymer replacement battery for the Xiaomi Redmi Note 9 Pro. It fits models 2409BRN2CA, 2409BRN2CC, 2409BRN2CG, and 2409BRN2CL, among others. OEM part number BN5X confirms direct fitment to this handset.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eRedmi Note 9 Pro platform fitment:\u003c\/strong\u003e\n    These model variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The BN5X part number is consistent across the regional hardware revisions listed, so one cell covers all of them without modification.\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 Redmi Note 9 Pro unit. The BMS accepted the cell on first connection, charge IC negotiated correctly, and the fuel gauge IC began tracking state-of-charge without manual intervention.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge recalibration tip:\u003c\/strong\u003e\n    After installation, disable fast charging for one complete discharge-charge cycle. The fuel gauge IC is calibrated to the old cell's discharge curve. Running one full cycle at standard charge current lets the coulomb counter reset its reference points before high-current fast charging pushes into 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\"\u003eWhy the Redmi Note 9 Pro reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC on this phone stores a learned discharge curve from the original cell. When a new cell goes in, the IC still references that old curve. This causes the percentage readout to lag behind actual cell voltage — the phone may report 40% while the cell is already below a stable load voltage. One full discharge-charge cycle at standard current forces the coulomb counter to rebuild its reference map against the new cell. After that cycle, percentage accuracy 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 is a voltage cliff issue, not a capacity fault. Under high load — active LTE, screen at full brightness, GPS — the cell voltage drops sharply. The phone's protection circuit shuts down when voltage sags below its threshold, even if the fuel gauge still shows charge remaining. The old cell had enough internal impedance history for the IC to anticipate this sag. With a new cell, the IC has no sag model yet. Run two full discharge-charge cycles to give the fuel gauge enough data to predict voltage behaviour under load, and the premature shutdowns will stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391780913242,"sku":"BWCS-XMR140SL-1","price":43.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391780946010,"sku":"BWCS-XMR140SL-2","price":51.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391780978778,"sku":"BWCS-XMR140SL-3","price":56.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-XMR140SL-1.webp?v=1779141928","url":"https:\/\/batteryweb.com\/products\/xiaomi-2409brn2ca-replacement-battery-384v-4750mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}