About this replacement
TomTom Go 940 / Go 940 Live — 3.7V Li-ion Replacement Battery (AHL03714001)
This is a 3.7V 1100mAh lithium-ion replacement battery for the TomTom Go 940 and Go 940 Live portable GPS navigators. It matches the original AHL03714001 specification and fits the same internal cavity. Voltage, connector, and physical dimensions (52.00 × 34.15 × 5.60mm) are matched to the original cell.
- Go 940 and Go 940 Live compatibility: Both models run off the same 3.7V cell with the same connector and BMS handshake. The Go 940 Live adds live traffic via a SIM module, which draws slightly more current during active use — this cell covers both variants without modification.
- Bench tested on actual hardware: We ran this cell on a Go 940 unit and confirmed the BMS accepted the charge cycle without fault flags, the device booted cleanly, and satellite acquisition completed normally within the expected cold-start window.
- First power-on after fitting: After fitting this cell, power the GPS fully on outdoors and let it acquire a satellite fix before driving. The device performs a cold start after any full power interruption — first fix can take 5–10 minutes outdoors with clear sky view, versus under a minute for subsequent warm starts.
GPS accuracy dropping at low battery on the Go 940
The Go 940 reduces receiver sensitivity as battery voltage drops toward the low-threshold cutoff. This is a power-saving measure baked into the firmware — the GPS receiver is one of the highest-draw components on the board. At reduced sensitivity, the device may drop from five or six satellites to two or three, which degrades position accuracy. Keeping the cell above roughly 3.5V maintains full receiver performance during active navigation.
Go 940 shutting off without warning before the battery indicator hits empty
This happens when the battery indicator hasn't been recalibrated after a cell swap. The firmware's charge model is still mapped to the old cell's discharge curve, so the visual indicator may show two bars while the actual cell voltage is already near the cutoff threshold. The BMS cuts power at the hardware voltage floor — typically around 3.0V — regardless of what the indicator displays. To recalibrate, run the device on battery until it shuts off naturally, then charge it uninterrupted to full. One full discharge-charge cycle resets the fuel gauge mapping.