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338 Posts
The very short version of the story is my battery will not charge/hold a charge. The car (2009 9-3 Aero SS) has been working fine until recently. Drove to a location about 100 miles away. After taking care of business I jumped in the car to go home and the battery was so dead that I couldn't get the key out. Someone stopped to help me out and got the car jumped ... started first try. On my drive home, I had my ScanGuage II running and monitored the voltage. It was 13.7v with nothing on and dropped to 12.5 with lights, fogs, radio, and AC on. This trip should have fully charged the battery.
After getting home, I turned the car off ... and then tried to start it again. Nope ... dead and locked the key in the ignition again. Called AAA out and they tested the system. They say the battery is good but detected "excessive ripple". No idea what that really means, but guessing rectifier is faulty and not normalizing the voltage from AC to DC. The next day I went out to put the battery on a charger to see if it would hold a charge and noticed the negative battery cable was very warm ... clearly flowing a lot of juice.
So, where is the likely problem? If I had a job I would probably take it to the shop to be fixed, but Looks like I need to do this on my own.
After getting home, I turned the car off ... and then tried to start it again. Nope ... dead and locked the key in the ignition again. Called AAA out and they tested the system. They say the battery is good but detected "excessive ripple". No idea what that really means, but guessing rectifier is faulty and not normalizing the voltage from AC to DC. The next day I went out to put the battery on a charger to see if it would hold a charge and noticed the negative battery cable was very warm ... clearly flowing a lot of juice.
So, where is the likely problem? If I had a job I would probably take it to the shop to be fixed, but Looks like I need to do this on my own.