anyone use an in-car mobile phone charger - silly question but please answer!

[amess]

Sorry to ask but an if you use one does it ever run down your car battery? Silly I know but cars are so touchy these days with all this technology have just been given one as a present and want to know if they cause problems!

Only use it when the engine is running..... I don't think they work when the car is switched off.

Ah I'm so thick I hadn't thought of that so they can't run the batter down then if the car is switched on can they! THANK YOU!

mien works with engine off too, and it still doesnt drain battery, they use so little power.

It will have a little red light on it.... mine only glows red when i turn the key to switch the engine on. It goes out (turns off) when I turn the engine off.