TomTom One XL HD Traffic K1 Replacement Battery 3.7V 1200mAh

TomTom One XL HD Traffic — 3.7V Li-ion Replacement Battery (K1)

This 3.7V, 1200mAh Li-ion cell replaces the original battery in the TomTom One XL HD Traffic portable GPS navigator. It fits the One XL HD Traffic and uses OEM part references K1 and FM0804001846. Swap it in when the original cell no longer holds a charge through a full navigation session.

• One XL HD Traffic fitment: The One XL HD Traffic runs a single-cell 3.7V Li-ion pack with a compact form factor — 43 × 35 × 9mm. The connector and BMS handshake match the original charge management circuit in the device, so the navigator reads state-of-charge correctly after fitting.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The BMS engaged correctly at both the low-voltage cutoff and full-charge threshold, and the device reported charge level accurately throughout.
• Cold-start satellite acquisition after fitting: After fitting this cell, power the device on outdoors and allow it to acquire a satellite fix before driving. The One XL HD Traffic performs a cold start after any full power interruption — first fix after a battery swap takes 5–10 minutes, versus under a minute on a warm start once almanac data is restored.

TomTom One XL HD Traffic shutting off without warning at low battery

After a battery swap, the One XL HD Traffic's charge indicator may not be calibrated to the new cell's discharge curve. The device can reach its low-voltage cutoff threshold before the on-screen battery icon shows critical. This happens because the fuel gauge has not yet mapped the new cell through a full cycle. Run one complete charge from flat to full and back to flat — after that cycle, the indicator and cutoff align correctly, and warnings appear at the right point.

Saved routes and POIs missing after battery replacement

The One XL HD Traffic stores most map and route data on internal flash, but some user-saved POIs and recent destinations sit in battery-backed volatile memory. Removing the original cell fully cuts power to that memory, which clears it. This is not a fault with the replacement cell — it is an expected result of a complete power interruption. Re-enter any custom POIs manually after the swap and allow the device to rebuild its recent destinations list through normal use.