When I sit in traffic(a4) the battery gauge goes down into the red zone(like 9 or less volts). If I throw it in park it goes up a bit. But it goes way down when i sit in traffic for a min or two stopped. Then today I drove for 10 min, turned off the car to go into the bank(like 2 min) Came back and turned it on...when I turn it on it ran for like half a second and shut back off. Then I turned it back on and it was fine.
I ordered some new plugs/wires, so those will be installed soon(hopefully that will solve my hesitation problem)

But I think this sounds like a battery right? Its going on I think 3 years old.

 

Have it checked at Autozone or someplace. Batteries rarely go past their expiration dates and sometimes they crapout before that. I buy a new battery when the date is up even if the thing is working fine.

It's cheap insurance against failure at the first cold snap. JMHO

 

mine was doing the samething...except, mine was the alternator...

 

Have your battery checked...if it's fine start looking at the alternator.

 

Autozone will check both for free right in the car.....takes 5 minutes.

Brad