PEAQ PMP300 3.7V Replacement Battery 900mAh Li-ion

PEAQ PMP300 — 3.7V Li-ion Replacement Battery

This 3.7V, 900mAh Li-ion cell replaces the original battery in the PEAQ PMP300 smartphone. It matches the factory voltage and capacity specifications so the device powers on and charges through the standard charge IC. Dimensions are 53.00 x 34.00 x 4.80mm — confirm your existing cell matches before fitting.

• PMP300 cell compatibility: The PMP300 uses a compact single-cell Li-ion pack at 3.7V nominal. This replacement matches that voltage rail and physical footprint so the battery connector seats without modification and the BMS communicates correctly with the phone's charge controller.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS held the 4.2V charge ceiling correctly, and the protection circuit tripped at the expected low-voltage cutoff without fault codes on the charge IC.
• Fuel gauge recalibration on first use: On first installation, disable fast charging if your charger supports it and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the OS starts reporting percentage — skipping this step causes erratic percentage readings in the first few days.

Sudden shutdown at 20–30% on the PMP300 after a cell swap

This happens because the fuel gauge IC is still calibrated to the old cell's discharge curve. A fresh cell has a steeper voltage drop near the bottom of its capacity range, and under modem or screen load the voltage sags below the protection threshold before the percentage counter reaches zero. The phone reads 25% but the cell voltage has already dropped to the cutoff point. One full discharge-charge cycle at standard rate gives the coulomb counter enough data to remap the curve — after that, shutdowns at mid-percentage stop.

Phone warm near the battery compartment during first charge

A new cell arrives with higher internal impedance than a broken-in cell. During the first charge cycle, the charge IC pushes current into a cell that hasn't yet settled, and that resistance generates more heat than normal. This is expected and reduces after one or two full cycles as the cell's impedance drops. If the device stays hot beyond the second full charge, check that the charger output matches the rated input — anything above the PMP300's specified charge voltage will keep the charge IC running hot indefinitely.