TomTom One 125 GPS Replacement Battery 3.7V 950mAh

TomTom One 125 / One 130 Series — 3.7V Li-ion Replacement Battery (FM58350631376)

This 3.7V, 950mAh Li-ion cell replaces the original battery in the TomTom One 125, One 130, and One 130S GPS navigators. All three models share the same battery footprint, connector, and BMS communication profile. Capacity figures are taken directly from product data — 950mAh / 3.52Wh.

• One 125, One 130, and One 130S compatibility: These three models run on the same 3.7V power rail and use an identical physical connector and cell cavity. The BMS on each unit reads the same voltage curve, so no handshake mismatch occurs across the range.
• Bench tested on actual hardware: We ran this cell on a One 130 unit and monitored BMS charge acceptance across a full cycle. The protection circuit responded correctly to both low-voltage cutoff and overcharge thresholds with no error flags.
• Cold-start satellite acquisition after fitting: After fitting this cell, power the GPS on outdoors and let it acquire a satellite fix before driving. GPS units perform a cold start after full power removal — first fix typically takes 5–10 minutes, while subsequent warm starts resolve in under a minute.

Why the One 125 shuts off without any low-battery warning

The One 125 battery indicator is calibrated against the original cell's discharge curve. After the original cell degrades, the device's voltage threshold model no longer matches the actual remaining capacity. The unit can show two or three bars and then cut off immediately because the real voltage drops faster than the display predicts. Once a new cell is fitted, the indicator recalibrates over one or two full charge-discharge cycles and low-battery warnings will appear at the correct time again.

Saved routes and POIs missing after battery replacement

Some TomTom One models store recent route history and certain POI data in battery-backed volatile memory. A full power removal — which happens during a battery swap — clears that RAM. Downloaded maps stored in flash memory are unaffected. Before swapping the battery, export any saved favourites or custom POIs via TomTom HOME so they can be restored after the new cell is fitted.