About this replacement
TomTom Spark 510 — 3.7V Li-Polymer Replacement Battery (PR-582035P)
This is a 3.7V, 320mAh lithium-polymer cell built to fit the TomTom Spark 510 GPS sports watch. It replaces the original PR-582035P battery when capacity fade makes the watch unable to hold charge through a full day of activity tracking. The cell measures 37.00 × 20.00 × 6.00mm and connects directly to the Spark 510's internal battery header.
- Spark 510 fit: The Spark 510 uses a compact LiPo format with a specific footprint and connector pitch tied to its GPS and heart rate sensor power rails. This cell matches that footprint exactly — no connector modification needed.
- Bench tested on actual hardware: We cycled this cell through the Spark 510's BMS and confirmed the protection circuit handled charge cutoff correctly at 4.2V and triggered low-voltage cutoff before the cell dropped below safe discharge thresholds.
- Post-swap charge requirement: After fitting the new cell, place the watch on its magnetic charger immediately and run it to 100% before first use. The Spark 510's fuel gauge IC loses its state-of-charge reference when the cell is swapped — skipping this step causes the watch to display 0% or shut off unexpectedly even with a full cell fitted.
Why the Spark 510 reads 0% immediately after a battery swap
The Spark 510 uses a fuel gauge IC that tracks charge by counting coulombs from a known reference point. When the battery is physically removed, that reference is wiped. The IC wakes up after the swap with no history, and without an initial full charge cycle it cannot estimate remaining capacity accurately. This causes the watch to show 0% or cut off at what appears to be a partial charge. Fix this by charging to 100% uninterrupted before turning the watch on for normal use.
Spark 510 not pairing with the phone app after battery replacement
Removing the battery drops power to the Bluetooth subsystem mid-session, which can corrupt the active BLE pairing state stored in volatile memory. The watch may power on normally but fail to appear in the TomTom MySports app or your phone's Bluetooth device list. This is not a battery fault — it is a lost session reference. Go to your phone's Bluetooth settings, forget the Spark 510 entry, then re-pair from scratch through the MySports app.