About this replacement
TomTom VIA 1505T Series — 3.7V Li-ion Replacement Battery (KL1)
This 3.7V, 900mAh Li-ion cell replaces the original KL1 battery in the TomTom VIA 1505T and related VIA-series GPS navigators. It fits the VIA 1435TM, VIA 1505M, and VIA 1405M among others. Same voltage, same connector, same footprint as the factory cell.
- VIA-series fit: These models share a common 3.7V single-cell architecture and the same KL1 connector pinout. The battery slides into the same bay with no modification. The BMS on each unit communicates over the same charge-control lines, so charge termination behaves identically to the original cell.
- Bench tested on actual hardware: We ran this cell on a VIA 1505T and confirmed the BMS accepted the charge cycle without fault, terminated at full voltage, and held standby draw at the expected level. No charge errors appeared on the status screen.
- First-use GPS cold start: After fitting this cell, power the unit on outdoors before driving. The GPS performs a cold start after any full power interruption — first satellite fix can take 5–10 minutes versus under a minute for a warm start. Let it acquire a full fix before you rely on navigation.
Why the VIA 1505T shuts off without warning at low battery
The VIA 1505T reads the battery's state of charge from voltage alone. After a swap, the on-screen indicator is uncalibrated — it hasn't mapped this cell's discharge curve yet. The unit can show two bars, then cut off seconds later because the actual cell voltage crossed the low-voltage protection threshold before the indicator caught up. This corrects itself after one or two full charge-discharge cycles, which re-establishes the voltage-to-percentage mapping the device uses.
Saved routes and POIs missing after battery replacement
Some user data on VIA-series devices is held in battery-backed RAM, not flash storage. When the original battery is fully disconnected, power drops to zero and that volatile memory clears. Favourites and recent destinations saved to RAM — rather than the internal storage — will not survive a full power removal. Before swapping, export any critical routes via TomTom HOME or MySports Connect to a backup file, then reload after the new cell is fitted.