I am buying an OBD2 Head Up Display. It has a screen where it shows readings etc. Manufacturer claims the item turns off when the engine is off too, and this is true from the videos I have watched. It turns off along with the ignition.
However, does that mean it uses absolutely ZERO battery when the engine is off? Or does it still use a tiny bit?
I am afraid of waking up to a dead battery one day, and if it uses 'minimal power', I am not sure how minimal it actual is if that makes sense.