12V Auxiliary Battery Failure
ModerateElectrics & ElectronicsThe small 12V battery runs the contactors and control modules. When it weakens, the car can throw random warnings or refuse to wake up despite the high-voltage pack being charged.
Multiple warning lights on startup, Car refusing to go ready, Intermittent locking, charging, or infotainment faults
- Ask for invoice proof of a recent 12V battery replacement
- Check whether the car wakes up cleanly after being left unused
- Be wary of sellers blaming repeated warnings on software alone