On 12 Dec 2003 14:29:05 -0800 in sci.electronics.basics,
was alleged to have written:
I've noticed that my new car allows draining of the 12 volt battery
through 12 volt sockets even when the ignition is off and the engine
is not running.

I use to leave charging devices attached to the car at night know they
would only charge while I drove around, but now I can't any more as
they will drain the primary battery.

Connect them to the accessory power lead that is switched on and off by
the ignition switch. Install a secondary power socket wired for that
purpose if you desire.