About this replacement
Mio MiVue 508 / 518 / 528 / 538 — 3.7V Li-Polymer Replacement Battery (FT402035P)
This 3.7V, 230mAh lithium-polymer cell replaces the internal battery in the Mio MiVue 508, 518, 528, and 538 dashcams. It restores the camera's ability to power on with the engine and maintain parking mode recording between drives. Dimensions are 36.80 × 20.10 × 4.00mm — confirm these against your existing cell before installing.
- MiVue 508–538 internal cell compatibility: These four models share the same internal battery bay, connector orientation, and BMS handshake. The FT402035P part number covers all of them — no firmware flag or voltage mismatch at startup.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the MiVue platform and confirmed the BMS accepted the cell without error flags, voltage held steady under sustained recording draw, and thermal output stayed within spec for a compact housing.
- First-cycle calibration after installation: After fitting a new internal cell, complete one full drive with the dashcam powered via the car charger before relying on parking mode. The dashcam's power management system calibrates parking mode duration against the new cell during that first charge cycle — skipping it can cause premature parking mode cutoff.
Why the MiVue 508 won't start recording on engine start after a battery swap
The MiVue 508 uses the internal battery as a buffer — it draws from the cell briefly before the car charger fully stabilises voltage on engine crank. If the new cell was installed fully discharged, the dashcam may not have enough charge to complete that startup sequence. Connect the dashcam to USB or your car charger for 15–20 minutes before expecting it to auto-start. Once the cell reads above 3.6V, normal ignition-triggered startup resumes.
Footage missing or corrupt after parking mode session
Parking mode clips get corrupted when the camera loses power mid-write. On a degraded or newly installed cell, voltage can sag below the dashcam's write-protection threshold before the file is closed cleanly. The camera cuts power to protect the SD card, but any open file at that moment is lost. Check that the cell is fully charged before a parking mode session and confirm your SD card write speed meets the MiVue's Class 10 minimum — slow cards increase the write window and the corruption risk.