I posted previously on the problem of an intermittent battory warning. It turned out to be the alternator but it was difficult to identify so if you get the following situation you will know what the problem is.
This occured during 2,500 to 3,000 miles of driving. The first four times the battery warning came on on the DIC it went off within 15 to 20 seconds then did not return for some hundreds of miles each time. The 5th time it came on I had driven around 1,000 miles since the last warning. It stayed on for around 5 miles of driving. About 50 miles later it came on and lasted around 10 miles. Took it to the dealer then and they were able to get it to come on again so could identify the cause.Had the car for 8 days getting an alternator from GM. Could have had it overnight from an auto supply. Go figure.
Main point is if you ever get any of these symptoms get it fixed so you don't get stranded on a trip somewhere.