I replaced 6 month old battery when it died overnight with a warranty replacement which died overnight the first night then a 2nd warranty battery which also died overnight the next night. None of these batteries would recharge on an external charger in or out of the car--what gives and is there anyway to save the last battery? Naturally I do not expect another warranty battery. I did have the system checked at the auto store after the last battery replacement and it supposedly was good. When I installed the last battery it showed 12.6 volts across the battery and 14.4 volts when car was running by my own voltage tests.