MeiZu M3e BA02 Replacement Battery 3.85V 3100mAh

MeiZu M3e / Meilan E — 3.85V Li-Polymer Replacement Battery (BA02)

This is a 3.85V, 3100mAh Li-Polymer cell carrying OEM part number BA02. It fits the MeiZu M3e, A680Q, A680M, and Meilan E smartphones. Dimensions are 75.00 × 65.00 × 3.70mm — measure your original before ordering if you are unsure of your variant.

• M3e / A680Q / A680M / Meilan E platform fit: These four models share the same battery bay geometry, connector pinout, and BMS handshake protocol — one cell covers all of them without modification.
• Bench tested on actual hardware: We cycled the BA02 through charge and discharge on the M3e platform. The BMS accepted the cell cleanly, charge termination triggered at the correct cutoff voltage, and no protection trips occurred under screen-plus-modem load.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. The fuel gauge IC on the M3e needs to map the new cell's discharge curve before it can report accurate percentages — skipping this step is the primary cause of erratic readings in the first week.

Sudden shutdown at 20–30% on the BA02 replacement cell

This is a voltage cliff issue, not a capacity fault. Under heavy modem or display load, the cell voltage drops faster than the fuel gauge IC expects based on its stored discharge curve. When voltage falls below the system's minimum threshold — typically around 3.4–3.5V at the rail — the phone shuts off even though the coulomb counter still shows charge remaining. One full calibration cycle resolves this in most cases. If shutdowns persist past three full cycles, check that the connector is fully seated and that contact resistance is not artificially loading the cell.

OS reporting wrong battery percentage after cell swap

The M3e's fuel gauge IC stores a discharge model calibrated to the original cell. After fitting the BA02, the IC applies that old model to a new cell with a different impedance profile, producing inaccurate percentage readings. The fix is a single full discharge — run the phone until it shuts down on its own, then charge uninterrupted to 100%. After that cycle, the coulomb counter resets its baseline against the new cell. If the reading is still jumping by more than 5% after two cycles, hold the phone at 3.85V on a bench supply for 30 minutes to stabilise the reference point before the next calibration run.