About this replacement
Xiaomi MI-ONE Plus / M1 / 1S / 2S — 3.7V Li-ion Replacement Battery (BM10)
This is a 3.7V, 1900mAh Li-ion cell built to replace the original BM10 battery in the Xiaomi MI-ONE Plus, M1, 1S, and 2S smartphones. It fits the same footprint at 63.78 × 40.94 × 6.03mm and connects via the original three-pin connector. Swap it when the stock cell no longer holds a charge or causes sudden shutdowns.
- MI-ONE Plus / M1 / 1S / 2S compatibility: These four models share the same battery bay geometry, connector pinout, and BMS handshake protocol, which is why a single BM10 cell covers all of them without modification.
- Bench tested on actual hardware: We cycled this cell through full discharge and charge sequences on MI-ONE Plus hardware. The BMS accepted the cell cleanly, protection thresholds tripped correctly at low-voltage cutoff, and the charge IC reached termination without error flags.
- Fuel gauge recalibration after install: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated cell.
Why the MI-ONE Plus reports wrong battery percentage after a cell swap
The fuel gauge IC on these devices uses a coulomb counter that was calibrated to the original cell's internal resistance and discharge curve. When a new cell goes in, those stored values no longer match the physical cell, so the reported percentage drifts — often reading full when it isn't. One complete uninterrupted discharge down to auto-shutoff, followed by a full charge to 100%, resets the calibration reference point. After that cycle, percentage accuracy returns to normal.
Sudden shutdown at 20–30% on a freshly installed BM10
This happens when the modem radio or display pulls a high-current burst and the cell voltage dips below the BMS protection threshold before the gauge reads zero. On a new, uncalibrated cell, the fuel gauge IC hasn't yet mapped the voltage cliff — the point where cell voltage drops sharply under load. The fix is the same recalibration cycle above. If shutdowns persist past the first full cycle, check that the connector is fully seated, as a loose contact raises effective impedance and deepens that voltage sag under load.