Bluetooth has nothing to do with Onstar. I do remember some problems with early Volts running 12v batteries dead with bluetooth staying active, but my '13 has never done it. You should just be able to unpair your phone. Be sure there's no keyfobs left near the car.
Yes, if you fully charge the battery and disconnect it, it should last for a month or more. That would be a good test. I just had a 15 mo old AGM battery die in my motorcycle, some kind of internal open connection. So they can fail prematurely. It won't even take a charge though. If you pull the Onstar fuse you will also lose hands-free calling (which also requires bluetooth). They're on the same fuse. (Ask me how I know!)
Properly working Volts have very low parasitic drain, under 30 ma as I recall. You could check it with a DC clamp meter.
Yes, if you fully charge the battery and disconnect it, it should last for a month or more. That would be a good test. I just had a 15 mo old AGM battery die in my motorcycle, some kind of internal open connection. So they can fail prematurely. It won't even take a charge though. If you pull the Onstar fuse you will also lose hands-free calling (which also requires bluetooth). They're on the same fuse. (Ask me how I know!)
Properly working Volts have very low parasitic drain, under 30 ma as I recall. You could check it with a DC clamp meter.
