MaxCom MM460BB Replacement Battery 3.7V 1050mAh Li-ion

MaxCom MM460BB / MM440BB — 3.7V Li-ion Replacement Battery (MM440BB)

This is a 3.7V Li-ion cell rated at 1050mAh (3.89Wh), built to fit the MaxCom MM460BB, MM440BB, MM462, and MM462BB mobile phones. It replaces the original cell when charge retention drops, the phone shuts down unexpectedly, or the battery no longer holds a usable charge. Voltage and connector pinout match the original spec across all four listed models.

• MM460BB, MM440BB, MM462, MM462BB fit group: These four models share the same 3.7V single-cell architecture, identical connector layout, and the same charge IC handshake. The BMS on each accepts the same cut-off and trickle-charge thresholds, so one cell covers all four variants without modification.
• Bench tested on actual hardware: We cycled this cell through charge and full discharge on the MM460BB platform. The BMS triggered overcharge protection cleanly at 4.2V and resumed trickle charge correctly after a simulated low-voltage drain event. No false full-charge flags appeared during the test cycle.
• First-cycle calibration tip for the MM460BB: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging is applied to an uncalibrated cell.

Why the MM460BB reports wrong battery percentage after a cell swap

The MM460BB uses a fuel gauge IC that builds its capacity model from accumulated charge and discharge data on the old cell. When a new cell goes in, that learned curve no longer matches the actual cell chemistry. The IC continues using the old model, which causes the displayed percentage to read high or low relative to true state of charge. One full discharge down to automatic shutdown followed by an uninterrupted charge to 100% forces the coulomb counter to reset and re-map against the new cell.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — typically during a call, when the modem draws peak current — and hits the BMS low-voltage cutoff before the displayed percentage reaches zero. The fuel gauge IC has not yet characterised the new cell's voltage-versus-capacity curve, so it misreads remaining charge. The fix is to complete two full discharge-charge cycles without interruption. After the second cycle, the gauge IC has enough data to shift the shutdown threshold to the correct voltage, which on this cell is approximately 3.0V under load.