About this replacement
Autel TS508K / MaxiTPMS TS508K Series — 3.7V Li-Polymer Replacement Battery (MLP604193)
This is a 3.7V, 2800mAh Li-Polymer replacement battery for the Autel TS508K and MaxiTPMS TS508K TPMS diagnostic scanner family. It fits the TS508K, xiTPMS TS408, MaxiTPMS TS508, and MaxiTPMS TS508K. OEM part number MLP604193, measuring 98.50 × 34.00 × 6.50mm — a direct physical and electrical match to the factory cell.
- TS508K / MaxiTPMS platform fit: The TS408, TS508, and TS508K share the same battery bay dimensions, connector pinout, and BMS communication protocol — one cell covers the whole line. The 3.7V nominal rail matches what the display driver, RF transceiver, and processor board each expect at the regulator input.
- Bench tested on actual hardware: We ran this cell in a TS508K unit and confirmed the BMS handshake completed without error flags. Charge acceptance was clean from a depleted state, and the protection circuit responded correctly to both overcharge cutoff and low-voltage trip thresholds.
- Pre-swap data export on the TS508K: The TS508K stores saved vehicle sensor profiles and registration data in RAM backed by the main battery. Pull that data to a PC via the Autel TPMS Desktop app before removing the old cell — once the battery is disconnected, that stored session data is gone.
Why the TS508K won't boot after a battery swap
A freshly installed Li-Polymer cell ships at a storage charge — typically around 3.6–3.75V — which sits right at the edge of the TS508K's boot voltage threshold. If the unit shows nothing on screen or flashes briefly then dies, the cell isn't flat — it's below the minimum the processor needs to initialise. Connect the charger for 20–30 minutes before pressing power. The scanner should boot normally once the cell clears approximately 3.8V.
RF signal dropping mid-sensor read at low charge
The TS508K's 315/433MHz RF transceiver draws a spike of current each time it activates a TPMS sensor. At low battery — typically below 3.5V under load — the voltage sags enough to destabilise the RF front end, causing incomplete reads or mid-sequence dropouts. The screen may still show 40–50% battery at this point because the display runs off a separate low-draw rail. If sensor reads start failing inconsistently, charge the unit before continuing — don't rely on the on-screen battery indicator alone.