BN48 Xiaomi Redmi Note 6 Pro Replacement Battery 3.85V 3900mAh

Xiaomi Redmi Note 6 Pro — 3.85V Li-Polymer Replacement Battery (BN48)

This is a 3900mAh Li-Polymer replacement battery for the Xiaomi Redmi Note 6 Pro smartphone. It fits the standard and Dual SIM variants, including M1806E7TE and M1806E7TC. Rated at 3.85V nominal and 15.02Wh, it replaces the original BN48 cell.

• Note 6 Pro platform compatibility: The Redmi Note 6 Pro and its regional variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol. All variants listed — including Dual SIM models — pull from the same BN48 specification, so one cell covers the full range without modification.
• Bench tested on actual hardware: We cycled this cell on a Redmi Note 6 Pro unit and monitored BMS communication throughout charge and discharge. The protection circuit responded correctly to charge termination and load cutoff. No false trips were recorded during modem-active discharge sequences.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one full discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Redmi Note 6 Pro after a cell swap

This happens because the fuel gauge IC is still calibrated to the old cell's voltage curve. The new cell hits a voltage cliff under combined modem and display load while the OS still reads 20–30% remaining. The phone sees an undervoltage condition and shuts down before the percentage reaches zero. One complete discharge to automatic shutdown followed by a full charge resets the coulomb counter and eliminates this behaviour.

USB fast charge not activating on the first cycle after replacement

Xiaomi's proprietary fast charge protocol requires a handshake between the charge IC and the battery BMS before elevated current is permitted. On a fresh cell, the BMS may reject the high-current request on the first cycle because it has no prior charge history to validate against. Charge once at standard rate using the OEM cable and adapter. Fast charging typically activates from the second cycle onward once the BMS registers a completed charge event.