TomTom Route XL GPS Replacement Battery 3.7V 900mAh

TomTom Route XL / One XXL 540S — 3.7V Li-ion Replacement Battery (P11P20-01-S02)

This 3.7V, 900mAh Li-ion cell replaces the original battery in the TomTom Route XL, One XXL 540S, XXL540, and XXL 540S GPS navigators. It restores power to the display, processor, and GPS receiver after the factory cell degrades or fails. OEM part number P11P20-01-S02 confirms fitment across this device family.

• Route XL and XXL 540S series compatibility: These models share the same battery bay dimensions, connector pinout, and 3.7V power rail, so one cell covers the full group without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Route XL platform. The BMS handled charge termination correctly and the device powered on without fault codes.
• Cold-start satellite acquisition after fitting: After any full power removal, the GPS receiver loses its almanac cache and must perform a cold start. Take the unit outdoors after fitting and leave it powered on — first satellite lock typically takes 5–10 minutes. Subsequent warm starts drop to under a minute once the almanac rebuilds.

GPS accuracy dropping at low battery on the Route XL

As the cell voltage falls toward the low-battery threshold, the Route XL reduces power to the GPS receiver to extend operation. Lower receiver sensitivity means the unit struggles to hold lock on weaker satellite signals, particularly in urban canyons or under tree cover. This is firmware-managed behaviour, not a hardware fault. Keeping the battery above 3.5V maintains full receiver sensitivity.

Device shutting off with no low-battery warning on screen

A new cell and a degraded original do not share the same discharge curve. The Route XL's battery indicator is calibrated against the original cell's curve, so it can read 20% remaining while the actual cell voltage has already reached the cutoff threshold. The BMS then trips and the unit powers off without warning. Run two or three full charge-to-cutoff cycles to let the firmware recalibrate its fuel gauge — after that, the on-screen indicator will align with the actual remaining charge.