A:Answer Anything that gets energy from your car battery while the engine is turned off has the potential to drain the battery, but with the extremely low current drain of a device like this it is unlikely, unless the device was plugged in while the car was unused for multiple days. It's safest to unplug it when the engine is turned off, or to find a power outlet in your car that is switched off along with the ignition. In my Honda, for instance, neither of the power outlets in the console work when the engine is turned off.
