I had my car towed in, I told them onstar diagnostic ssid it was more than just the battery, check the charging system. I was told it's just the battery. They changed out the battery Thursday. Friday afternoon car was acting up, i called my service advisor he said they might be able to look at it today but probably wouldn't be worked on till Mobday as Saturday was all booked. I called Chapman Chevrolet, thry got it fixed about 1 Saturday (replaced alternator ). Problem solved.