Ive searched around the boards regarding issues with 997 batteries. Apparently there is a TSB on them, how to maintain, charge etc...From what I've read, others have weird window problems (going up and down for no reason). Mine has been doing this same thing since I got it. When you turn it over it starts very slow and will eventually dies after a day or so of non use. When I plug my jumpbox into it to start it, I get PSM failure, PASM failure, Sport mode failure, windows going up and down for no reason, windshield wipers deploying, seat moving on it's own...all kinds of weird stuff.
The first time it happened the (idiot) dealer recharged the battery. The second time they replaced the battery. Now, it's dead again and I'm hesitant to take it back to these same inept morons because there is clearly SOME OTHER problem that's causing the bttery drain.
Does anyone know what the cause of this is ???

 

Did you check all of your fuses?

I have the window issue when I put my passenger window up - the dealer said it's an overly sensitive anti-pinch sensor. I'll get it fixed when I have something else worth fixing.

 

is there another dealer? i've not heard of such issue.

 

I've checked all the fuses and they are all fine. The next closest dealer is about 35 mins away, which is no big deal.
I'm thinking there is some sort of draw on the electrical system while the car is switched off....
I used my jump box and charged it overnight and it seems fine now. But, I know it's going to happen again...

 

Don't know if it would apply to the Porsche, but I have dealt with this on MB's and sounds like a Conv. Control Module, system supplying constant power, not recognizing vehicle is in "sleep" mode; causing the dead battery. And when the vehicle is charged and running, all the systems start working at times when they are not needed.

Jim