About this replacement
Medion GoPal P4425 / P4225 — 3.7V Li-ion Replacement Battery (T0052)
This 3.7V 1100mAh Li-ion cell replaces the original T0052 battery in the Medion GoPal P4425 and GoPal P4225 series portable GPS navigators. It fits both the standard P4225 and the P4225 M5 variant. Capacity matches the OEM specification at 4.07Wh.
- GoPal P4425 and P4225 series fit: These models share the same battery bay dimensions, connector pinout, and 3.7V single-cell charging circuit. One cell covers both navigation units without any modification.
- Bench tested on actual hardware: We ran this cell through full charge cycles on the GoPal P4425 and confirmed the BMS accepted charge without triggering overcharge protection. Voltage at full charge measured 4.18V — within the 4.20V ceiling the device controller expects.
- First power-on after fitting: After fitting this cell, power the unit on outdoors and let it acquire a satellite fix before driving. A cold start after full power removal takes 5–10 minutes for first lock. Subsequent warm starts drop back under a minute once the almanac is cached.
GPS accuracy reduced at low battery on the GoPal P4425
When cell voltage drops below roughly 3.5V, the GoPal P4425 reduces power to the GPS receiver to extend operation. Lower receiver sensitivity means the unit holds fewer satellites and position accuracy degrades — sometimes by 10–20 metres. You may notice the blue dot on-screen drifting or snapping to road incorrectly. Fitting a fresh cell and charging to full restores the receiver to full sensitivity immediately.
GoPal P4425 shutting off without low-battery warning
An aged or deeply discharged cell loses the flat mid-discharge voltage plateau that the device uses to estimate remaining charge. The on-screen indicator reads three bars, then the unit cuts off — no warning shown. This happens because the voltage drops sharply below the shutdown threshold before the indicator recalibrates. Run two full charge-and-discharge cycles after fitting the new cell to let the fuel gauge re-anchor its reference points.