About this replacement
OTC Genisys EVO Series — 9.6V Ni-MH Replacement Battery (239180)
This is a 9.6V, 1200mAh Ni-MH replacement battery for the OTC Genisys and Genisys EVO diagnostic scanners. It also fits the Cornwell Tech/Force and Supreme/EVO platforms that share the same battery bay and connector. OEM part number 239180 confirms the fit across all listed models.
- Genisys platform compatibility: The Genisys, Genisys EVO, Cornwell Tech/Force, and Supreme/EVO all use the same 9.6V Ni-MH cell pack with the same connector and BMS handshake. OTC standardised the battery bay across these platforms, so one SKU covers the full group.
- Bench tested on actual hardware: We cycled this battery through a full charge and discharge on the Genisys platform. The BMS accepted the pack without fault codes, and the scanner held stable voltage across a live OBD session pulling real-time data from multiple modules.
- Ni-MH conditioning on the Genisys: Ni-MH cells in the Genisys are susceptible to voltage depression from repeated partial charges. Run at least two full discharge-charge cycles after fitting this battery to reset the cell balance and recover full usable capacity.
Saved vehicle profiles disappearing after a battery swap
The Genisys stores vehicle profiles and session data in RAM that draws power directly from the main battery. When the battery drops below the memory-hold threshold during a swap, that RAM loses its state and the data is gone. This is not a firmware fault — it is a power interruption to volatile storage. Export all saved vehicle profiles to the SD card or PC before pulling the old battery.
Scanner screen dimming before the battery indicator shows low
The Genisys display driver is voltage-sensitive and begins throttling backlight output before the battery management circuit logs a low-battery warning. This happens because the display draws from the same rail as the rest of the unit, and backlight dimming is the first visible sign of voltage sag. It is not a screen fault. Charge the battery until the indicator shows full — typically at 11.5V resting — before starting the next session.