I took my 2010 automatic cobalt into a transmission shop for troubleshooting. It has been shifting poorly in the lower gears and stalling at stops unless I manually shift instead of using D (Drive). At first they told me the battery was bad, which made sense since the car had been sitting a long while and I did have to jump the battery twice that day, so I picked up a new battery under warranty and dropped it off. The shop called shortly after telling me that the new battery also tested bad but only when installed in the vehicle. Tested outside of the vehicle it passes. They continued to tell me there must be an electrical issue and that I need to take it to another shop that could diagnose it. So now I am left puzzled about what could be causing the battery to test bad only when it is installed. The car starts up just fine with the new battery and as far as I can tell with a multimeter there is no parasitic drain which also makes sense since the car starts right up after sitting over night. Any suggestions in trying to troubleshoot this would be helpful.