About this replacement
Rand McNally TND-510 / TND-530 Series — 3.7V Li-Polymer Replacement Battery (EU504046P)
This 3.7V 950mAh lithium-polymer cell replaces the OEM battery in the Rand McNally TND-510, TND-520, TND-525, and TND-530 truck GPS navigators. It matches the original EU504046P spec and fits the same battery bay without modification. Capacity is 950mAh (3.52Wh), identical to the factory cell.
- TND-510 through TND-530 compatibility: These four navigators share the same battery bay dimensions, connector pinout, and voltage rail. The EU504046P part number covers all four models, so one cell fits the full series without any wiring or connector changes.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the TND platform and monitored BMS cutoff behaviour. The protection circuit held within spec at both ends of the voltage range — no premature cutoff and no overcharge pass-through.
- Cold-start satellite acquisition after swap: After fitting this battery, power the unit on outdoors and let it acquire a full satellite fix before driving. The TND-510 performs a cold start after any complete power interruption — first fix can take 5–10 minutes outdoors, compared to under a minute for a warm start once GPS almanac data is rebuilt.
GPS accuracy reduced when the battery charge drops low
The TND-510's GPS receiver draws continuous power to maintain satellite lock and process positioning data. At low charge, some units reduce receiver sensitivity to stay within the power budget, which can degrade fix accuracy or cause brief signal drops. This is a firmware-level power management decision, not a hardware fault. Keeping the unit charged above 20% during active navigation avoids this threshold.
Saved routes and custom POIs missing after battery replacement
The TND series stores some user data in battery-backed RAM, which loses its state when power is fully removed. Swapping the battery counts as a complete power interruption, so custom POIs and saved routes may not survive the swap. Rand McNally's TND desktop software can back up route data before you open the unit. Export your routes via the software first, then restore after the new cell is fitted and the device boots cleanly.