About this replacement
TomTom Go 1000 Series — 3.7V Li-ion Replacement Battery (AHL03711018)
This is a 3.7V, 1000mAh Li-ion cell that replaces the original battery in the TomTom Go 1000, Go 1005, Go 1000 Live, and related models including the 4CS0.002.01. It fits the thin 42 × 36 × 5mm battery bay and connects via the original two-pin ribbon connector. Voltage and capacity match the factory spec exactly.
- Go 1000 and Go 1005 shared platform: These models run the same mainboard revision with identical voltage rails, connector pinout, and BMS handshake protocol — one cell covers all variants listed above without any modification.
- Bench tested on actual hardware: We cycled this cell on a Go 1000 unit through full charge and discharge while monitoring BMS communication. The protection circuit responded correctly to both overvoltage and undervoltage cutoff thresholds throughout testing.
- Cold-start satellite acquisition after swap: After fitting this cell, power the Go 1000 on outdoors and let it acquire a satellite fix before driving. Full power removal triggers a GPS cold start — expect 5 to 10 minutes for first lock versus under a minute once almanac data is cached.
GPS accuracy reduced at low battery on the Go 1000
When cell voltage drops below approximately 3.5V, the Go 1000 reduces power to the GPS receiver to extend operation. This lowers receiver sensitivity and can cause position drift or loss of fix in weaker signal areas like urban canyons or car parks. You may see the position marker jump or lag behind your actual position. Keeping the device plugged into the car charger during navigation eliminates this issue entirely.
Go 1000 shuts off without a low-battery warning
The fuel gauge IC on the Go 1000 mainboard learns capacity from charge cycles — after a battery swap it has no baseline to work from. It can show 20% remaining right up until the cell hits the BMS cutoff voltage and the unit powers off without warning. Run two full charge-to-discharge cycles via the car charger or mains adapter to let the gauge recalibrate. After that, the battery indicator will track remaining charge accurately again.