About this replacement
TomTom One V1 — 3.7V Li-Polymer Replacement Battery (GLASGOW / F54629631)
This 3.7V, 1350mAh Li-Polymer cell replaces the original battery in the TomTom One V1 portable GPS navigator. It fits the One V1 directly, matching the OEM voltage, connector, and physical footprint. Use the Capacity field figure of 1350mAh (5Wh) — that is the rated spec for this cell.
- One V1 fitment: The One V1 uses a slim Li-Polymer pouch cell with a specific pin-out for the onboard charge controller. This cell matches that voltage rail and connector geometry so the charge controller recognises it without fault flags.
- Bench tested on actual hardware: We cycled this cell through the One V1's charge controller and confirmed the BMS accepted the cell, reached full charge without thermal events, and passed current to the display and GPS receiver under load.
- Cold-start satellite acquisition after swap: After fitting this cell, power the unit on outdoors and let it acquire a satellite fix before driving. A full power interruption wipes the assisted GPS cache, so the first fix after a battery swap can take 5–10 minutes. Subsequent warm starts return to under a minute.
GPS accuracy dropping as the battery level falls on the One V1
The One V1's GPS receiver draws the most current of any subsystem in the unit. At low battery voltage — typically below 3.5V — the device reduces receiver sensitivity to protect the remaining charge. This appears as position drift or slower recalculation, not a software fault. Keeping the cell above 3.6V during navigation maintains full receiver performance.
One V1 shutting off without a low-battery warning
The fuel gauge in the One V1 is calibrated against the original cell's discharge curve. A new cell — or a worn cell — can cause the indicator to read 20% while actual voltage is already at the cutoff threshold. The device then shuts off without the expected warning screen. Running two full charge-discharge cycles recalibrates the gauge and restores accurate low-battery alerts. After the second cycle, the warning should appear at the correct voltage, around 3.5V.