For no apparent reason, my Q7 has gone completely dead just over night twice now, once in May last year and once just recently. I live in California, so the weather is warm, I have no aftermarket electrical equipment, and I don't drive unusually short distances. The battery was so drained that the car could not even be jump started by the towing company.

The dealer claims the battery takes the charge and everything checks OK. The last time it happened, they mentioned that my vanity light in the right sun visor was on and said that was the reason. I don't buy that, as it is turned off automatically, I checked that myself.
Not only did I have to tow the car both times, but the dealer also charged me $145 for recharging the battery :-(. I claim it's a technical issue, but because the dealer cannot find a problem, they don't want to file a warranty claim. The money is one thing, but even worse is if this happens again, in an inconvenient place.

I've seen a few postings on this forum regarding dead batteries, but I've not seen any resolution or found problems. Has anyone else experienced a dead battery with your Q7? Any suggestion on how to get to the root cause would be greatly appreciated?

Many thanks
-Per

Earth strap and battery protection failure offered within replies.
<a href="http://forums.audiworld.com/q7/threads/2126.phtml#13319">azatty thread</a> one possible solution offered.
<a href="http://forums.audiworld.com/q7/threads/2898.phtml#17983">Millenium thread</a> no help to you but how to remove key solution offered.
<a href="http://forums.audiworld.com/q7/threads/2943.phtml#18204">Goldmember thread</a> offering reset solution for MMI

You probably saw these already!

No start condition after sitting over night. One fault in the power management module claiming an unknown condition. Battery took a charge (looked like a shorted cell) and would start but dealer advised and arraged for a flat bed tow in to the shop.

This was in early November and they have ordered new software for the MMI. The explanation was that the radio does not turn off correctly in some conditions and the MMI update addresses this. However, no CD/DVD has yet made it from the factory to my dealer. Possibly in a few weeks, then I'll have the 30 minute update performed.

Since then no repeat fo the condition.

First time was 1 week after delivery(end of March 07). Ours was custom ordered so the battery was installed within a couple of weeks of delivery. Dealer checked the battery and said it was fine. All has been well until last week when it was dead again- this after I had trickle charged it the week before. After jumping it I have not had it die again. I am sure having the battery die multiple times is not good for its longevity. I am contacting the dealer about the "MMI update" others have mentioned to see what they say. Nothing had been left on in the car either time.

Thanks for responses. I'll take this to the dealer and will let you know what I find out.

Thanks
-Per

I just blamed on my wife; and also the dog jumping on the MMI controls. I will follow your post for MMI software solution.
I have been always able to jump start the battery.

I know, I also thought it was the dog, kid or wife, but the power control system on the Q7 is suppose to turn things off automatically. I tested this with the interior light, vanity light etc and it seems to work. Tried jump starting the car both times, but was not able to get enough power to turn the engine, even from the towing truck. I've not yet heard back from the dealer, who's checking the MMI update with the rep. Will let you know as soon as I hear back.