Batteries
In a hybrid and a battery electric EV vehicle there is both a high-voltage battery pack (to power the electric motor that drives the vehicle), and there is still a 12-volt battery.
A 12-volt battery is a standard lead-acid battery used in most traditional internal combustion engine vehicles. It is typically used to power the vehicle's electrical system, such as lights, radio, and other accessories.
The 12-volt battery is used to power the hybrid vehicle's conventional electrical system such as window wipers, and also provide power for vehicle safety systems. This 12 volt battery is critical and should be regularly tested in all Hybrid and EV vehicles.