Meilan M5 Compatible Battery 3.85V 3000mAh Li-Polymer

Meilan M5 / 5 — 3.85V Li-Polymer Replacement Battery

This 3.85V, 3000mAh Li-Polymer battery replaces the original cell in the Meilan M5 and Meilan 5 smartphones. It fits the M5's internal battery bay at 78.44 × 62.74 × 3.38mm and reconnects to the stock charge IC and fuel gauge IC without modification. Capacity is 3000mAh (11.55Wh), matching the original cell specification.

• M5 and Meilan 5 platform fit: Both the M5 and Meilan 5 use the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers both variants without adapter or wiring change.
• Bench tested on actual hardware: We ran charge and discharge cycles through a Meilan M5 unit on the bench. The BMS accepted charge without fault, the fuel gauge IC tracked state-of-charge through a full cycle, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• First-cycle fast charge hold-off: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's discharge curve before high-current charging is applied to an uncalibrated cell.

Why the M5 reports wrong battery percentage after a cell swap

The Meilan M5 uses a fuel gauge IC that builds its state-of-charge model from the old cell's impedance and discharge curve. When a new cell goes in, that learned model no longer matches the actual chemistry. The gauge reads voltage correctly but maps it to the wrong capacity percentage. One full discharge down to automatic shutdown followed by a full charge to 100% forces the coulomb counter to reset and relearn the new cell's curve. After that cycle, percentage reporting stabilises.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem radio or display pulls a high current burst and the cell voltage drops sharply below the BMS cutoff threshold — even though the gauge still shows charge remaining. It is a voltage sag issue, not a capacity defect. The BMS sees the instantaneous voltage cliff and cuts power to protect the cell. After the first two or three full discharge-charge cycles, internal resistance settles and the sag narrows. If shutdowns persist past three cycles, check that the battery connector is fully seated — a loose pin raises contact resistance and worsens voltage drop under load.