vw taschenlampe any good for upstairs?

[Waldo]

I had one of these : http://www.amazon.de/dp/B004VPX1TM/
I think it is small enough to keep it permanently in the 12 V socket under the roof (I mean with the roof down). Can anyone confirm?
I'm not sure mine ever worked, can anyone explain how it works? Turn to charge or turn to switch on?
Does it have to charge a long time the first time?
(cannot find mine now, if it is any good I'll look for it, if it's rubbish I'll forget about it)