Car Dead

[lawfam]

We went on vacation for a week. We left the car plugged in. When we returned the car is completely dead.  Our car went dead once before and it was the 12volt battery. We had it replaced. It has only been two years since we replaced it.  Can I manually charge the 12 volt battery to see if it dies again or to see if it will even take a charge. Or should I start somewhere else.  Last time we had to have it towed and it is quite an ordeal when the car has zero power to have it towed as nothing will engage: cant get it out of gear, no stearin etc.  Any thoughts on where I should start?

[jsamp]

If it was plugged in the whole time, the HVB should be charged.  A jump should bring it to life.  Of course, with a dead 12V it will only last until you shut it off again, but at least you can confirm that the HVB is full.  Personally I'd put the 12V on a charger for a night and see how it's doing the next morning.

[13 C-Max Energi]

My '13 C-Max Energi had a similar problem and it was due to the audio control module computer staying in an "on" setting and draining the 12 V battery. You can charge the 12 V battery - using the remote connections under the hood makes the job fairly easy. In our case, we had been experiencing the radio getting stuck on (even with the car turned off) and I had to pull the fuse briefly to reset it. That's on the same circuit as the audio control module. Pulling that fuse out also stopped the drain on the 12 V battery but it's a temporary fix since the hazard warning lights are disabled unless you put the fuse back in. We then took it to the Ford dealer who's mechanic reset the audio control module. No idea what that means, but they didn't charge us anything and the problem has been gone since then, nearly 2 years ago.