I bought a cheap ($1.61!) voltage indicator to plug into the 12v port in the center console. Yes, it does stay on, for a while, but eventually that port turns off. No reading until I open the door, then it wakes up, and usually shows about 12v. I have seen 10.5v for a short time while cranking, and 14.3v or so at times while charging. I did the disconnect (thanks Unhinged) and solved my early problems.

 

Ah, so! Yes, the cigarette lighter socket behaves the same way; once the car is locked, it is off. Thanks; I learned something.

 

Just told my dealer "Please, do not make me go to Batteries + and buy a new battery", getting the same old runaround, with a twist "It is normal to get the, battery low start the car message, every now and then" I started laughing....

 

I have a new car with 100 miles driven so far. Went to the garage after not driving it for a few sprays and it is dead!

 

Just wait until you get to the dealer.. they will say they can't detect any problem and need to reproduce the problem before doing anything.

 

They probably tapped into the obdII to prep the car. Disconnect the battery for at least 10 seconds and the energy control module should reboot itself and solve the problem.