Moosp
If you disconnect the battery and then stick your head in the boot (trunk) and reconnect the battery, you'll here a relay 'click'. I don't know which relay or why, but I know if it clicks when you add power, it must be drawing some current, however small.
That's why I always disconnect the battery.
PS. Don't try to disconnect or reconnect the battery when you're in a hurry as my freind did. He had his car keys in the same hand he was trying to turn the battery terminal with. A bright flash and some instantaneous arc welding later and he was stuck .... car ignition key welded to the battery terminal! Couldn't start the chopper because he couldn't get the batt connected; couldn't start the car because his key was welded to the batt and to cap it all, there was no mobile phone signal to call for help! Why does it always come in threes?
J
J