I left my heated seat plugged in to my cigarette lighter.

[Joey_P]

@terrymiff

I’d get someone to check the wiring to your cigarette lighter. Every car I’ve ever driven was built so that the cigarette lighter was only powered when the ignition was at least in the “accessories” position. The only way that the seat heater should flatten the battery would be if the car was left with the keys in and switched to “accessories” or “on”.

Totally depends on the car. My Civic turns off the lighters when the car is off, OTOH my friends VW wagon (passat maybe) does not.