A dead 12-volt battery can be caused by lack of use. An EV’s low-voltage system is always ON, powering various computers and controlling modules, even when the vehicle is OFF.

Some 12-Volt Battery Background For over a half-century, 12-volt batteries were engineered and optimized to provide the cold cranking amps needed to start an internal combustion engine when it was ...

In an internal combustion vehicle, the battery is charged by the alternator when the engine is running. In the Mach-E (and most EVs), the 12-volt battery siphons off some of the energy from the ...