About this replacement
TomTom Eclipse / AVN4430 / TNS410 — 3.7V Li-Polymer Replacement Battery (AHL03713001)
This 3.7V, 1200mAh Li-Polymer cell replaces the original battery in the TomTom Eclipse, AVN4430, and TNS410 portable GPS navigators. It matches the OEM dimensions at 59.00 × 37.00 × 5.30mm and connects directly to the factory connector. Capacity is drawn from product data — 4.44Wh total energy.
- Eclipse / AVN4430 / TNS410 platform fit: These three models share the same battery bay geometry, connector pin-out, and BMS handshake voltage. One cell covers all three without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the GPS platform. The BMS accepted the cell cleanly, hit full charge cutoff at 4.2V, and triggered low-voltage protection at the correct threshold without false cutoffs.
- Cold-start satellite fix after battery swap: After fitting this cell, power the GPS fully on outdoors and let it run until it acquires a satellite fix. The device performs a cold start after any full power interruption — first fix typically takes 5–10 minutes versus under a minute on a warm start. Do not interrupt power during this window.
GPS navigator losing saved routes after battery swap
The Eclipse and related models store some route and POI data in battery-backed RAM. When the original cell is fully discharged or physically removed, that volatile memory loses power and the stored data clears. This is not a fault with the replacement cell — it is a consequence of full power removal. Before swapping the battery, export saved routes to the TomTom MyDrive account or to an SD card so they can be restored after the first boot.
Device shuts off without warning at what looks like half charge
After fitting a new cell, the fuel gauge IC on the device may still be calibrated to the old battery's degraded discharge curve. It reads the remaining capacity incorrectly and does not trigger the low-battery warning icon until the cell is already below the shutdown threshold. Run the device through two full charge-to-cutoff discharge cycles on active navigation — this recalibrates the gauge to the new cell's actual curve and restores accurate warning behaviour. Target a resting voltage of 3.7V mid-cycle as a reference point that the gauge should read as approximately 50% charge.