TomTom ONE 1EK0.052.02 Replacement Battery 3.7V 950mAh

TomTom 1EK0.052.02 / Go 500 Series — 3.7V Li-ion Replacement Battery (AHA11110005)

This 3.7V 950mAh Li-ion cell replaces the original battery in TomTom ONE and Go 500 series portable GPS navigators. It fits models 1EK0.052.02, 4EK0.001.02, Go 50, and Go 500, among others. Voltage and connector match the original — no modification required.

• Go 50 / Go 500 platform fit: These models share the same 3.7V single-cell architecture, connector pinout, and BMS handshake requirements. One cell covers the full group.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Go 500 unit. The BMS accepted the cell without error flags, and charge termination triggered correctly at 4.2V.
• Cold-start satellite acquisition after fitting: After any full power interruption, the GPS module loses its almanac cache and must perform a cold start. Take the device outdoors immediately after first power-on and leave it stationary. First satellite fix can take 5–10 minutes. Subsequent warm starts drop to under a minute once the almanac is rebuilt.

Why the Go 500 shuts off without showing a low-battery warning

TomTom's battery indicator is calibrated to the original cell's discharge curve. A new cell — or one that has aged differently — can hit the device's low-voltage cutoff threshold before the on-screen indicator reaches the red zone. The GPS processor draws a sharp current spike during active route calculation, which causes a brief voltage sag. If the cell's resting charge is already near the cutoff, that sag triggers an immediate shutdown. Charge the unit fully before relying on the indicator — a full charge reads 4.2V at the cell terminals.

GPS accuracy dropping off during long navigation sessions

Some TomTom units reduce GPS receiver sensitivity when the battery drops below a set threshold — this is a firmware-level power-saving measure, not a hardware fault. Reduced receiver gain means the unit struggles to hold lock on weaker satellite signals, particularly in urban canyons or under tree cover. You will notice this as position jumps or the route line drifting off the road. Keep the unit plugged into the vehicle charger on long trips to hold the battery above the threshold and maintain full receiver performance.