Yes — your Tesla, ID3, EV6 or e-tron still has a 12V battery. And it still fails — often more dramatically than on petrol cars, because nothing wakes up if the 12V is flat.
Why EVs have a 12V battery
All low-voltage systems (lights, infotainment, door locks, BMS, contactors) run on 12V. The HV battery only powers the motor and the DC-DC converter that tops up the 12V.
Why they fail more often
EV 12V batteries are smaller and constantly cycled by the always-on telematics and BMS. Many die at 2–3 years.
Symptoms
Car won't 'boot up', no screen, doors won't unlock, dead frunk release. Owners often assume the HV battery has failed — almost never the case.
Replacement
Mobile EV 12V battery replacement is a careful job — proper isolation procedure, correct AGM/Li-ion replacement, and BMS reset. Don't let a generalist tow you to a dealer for a £180 battery.