12V Battery Drain & Deep Sleep Bugs
ModerateElectrics & ElectronicsThe auxiliary 12V battery can drain if the car is left for several days. On earlier models, this was often due to the car failing to enter a "deep sleep" mode, sometimes exacerbated by frequent Bluelink app pings or third-party tracking apps.
Est. Repair Cost: £120–£200
Warning Signs:
Car completely unresponsive, Remote locking fails, Clock resets, 12V battery dies if HV battery is below 20%
What to Inspect:
- Age and health of the 12V battery
- Presence of a "Battery Reset" button (on newer models)
- Software version of the BMC
Verified by IsItAGoodCar Research Team