Meilan U10 Compatible Battery 3.85V 2750mAh Li-Polymer

Meilan U10 / U680 Series — 3.85V Li-Polymer Replacement Battery

This is a 3.85V, 2750mAh lithium-polymer cell that replaces the original battery in the Meilan U10, U10 Dual SIM, U680A, and U680D smartphones. It matches the original voltage rail and physical footprint at 74.10 × 59.30 × 3.40 mm. Install it when the original cell no longer holds charge or causes unexpected shutdowns.

• U10 and U680 platform fit: The U10, U10 Dual SIM, U680A, and U680D all run the same 3.85V single-cell architecture with an identical connector pinout and BMS handshake protocol. One cell spec covers all four variants without modification.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on U680-series hardware. The BMS accepted the cell on first connection, protection thresholds triggered correctly at both ends of the voltage range, and the charge IC engaged without fault codes.
• Fuel gauge recalibration on first install: After fitting this cell, disable fast charging and run one complete discharge down to automatic shutdown, then charge to 100% on a standard 5V/1A cable. This gives the coulomb counter a clean reference curve before high-current charging sessions begin.

Why the U10 reports wrong battery percentage after a cell swap

The fuel gauge IC on the U10 stores a discharge curve calibrated to the original cell. When a new cell goes in, that stored curve no longer matches the actual charge state of the replacement. The IC reads voltage and estimates capacity against the old data, so the percentage shown on screen drifts from reality — often reading 40% while the phone is close to shutdown. One full discharge-charge cycle on standard current forces the IC to overwrite the old curve with data from the new cell. After that cycle, percentage reporting stabilises.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem, display, or both draw a current spike that the cell cannot sustain at its current state of charge — the terminal voltage drops below the BMS cutoff threshold, and the phone shuts off even though the gauge still shows remaining capacity. It is a voltage-sag issue, not a faulty cell. The BMS is doing its job. Run the fuel gauge recalibration cycle described above — once the coulomb counter has accurate data, it accounts for voltage sag at lower charge states and the shutdowns stop. If they continue after two full cycles, verify the charge IC is delivering a clean 4.35V cutoff at full charge.