Trickle charger OK for non-Porsche?

[JimEE]

I have the Porsche trickle charger (plugs into the cigarette lighter socket) and had it plugged in to my Boxster S all winter while I drove my sedan. It worked great. The Boxster started right up after sitting for a few months. Now I'm driving the Boxster and letting the sedan sit (BMW 525). After a couple weeks sitting, the sedan failed to start due to a weak battery.

My question is, will the Porsche trickle charger that plugs into the cigarette lighter work on cars other than Porsche's? Maybe the eletrical circuitry in cars is all similar enough that a trickle charger/cigarette lighter plug works the same for all cars. Maybe not.

Thanks, Jim

[Loren]

That would depend on if the lighter socket on the BMW is unswitched (always on).

On Porsches they are always on - I know my Mercedes is the opposite (always off).

So, if the lighter does not work with the ignition off and the key out -- then you won't be able to charge the battery through the lighter socket.

[JimEE]

Thanks, Loren! Just what I wanted to know.

Jim