Trickle Charger
 

Can anyone confirm that a trickle charger/maintainer (Porsche brand) plugged in through a cigarette lighter will not hurt the electrical system?

I think some already mention that it won't work because the lighter circuit is turned off when the ignition is turned off.

We use a charger like that on Aircraft that sits a long time, the best one to get is a Battery Minder. You have to hook to the battery or some post that is hot when the car is off. It will not harm anything.