I have tried different USB chargers that fit in to the car cigarette lighter socket within the armrest.

I noticed that lights on the various USB charger is always on even with the ignition off and when the car is locked.
- does anyone know if this will kill the battery?
- OR it turns off after a certain amount of time?

 

It is a live socket. If you're charging something it will certainly drain the battery over a long time. But there are plenty of electronics in the car that are in "standby" that are also draining the battery. Which is why a maintainer is mandatory on this car if it regularly sits for weeks at a time. The live socket allows you to plug the maintainer into it. If it turned off with the ignition, you would need to find another source of power to the battery. I use the terminal under the hood, personally, because I don't like closing the door on the charge cable.

 

it runs through a 20a fuse in the fusebox on the passenger side floorboard. it is pretty much not mentioned in the manual, and marked 'spare' on my 2007 vantage fusebox. it is, as mentioned previously, not switched. some say it's fuse 55. it may be. i can't remember.