What makes a car not keep a charge?
Generally when a car battery does not keep a charge it means
that the battery is shot or that you will need to replace the
alternator. You can check this by either taking it to your local
parts supplier. For example: Advance Auto Parts or Auto zone which
can both test your battery easily and there is usually no to little
charge for this service. On the other hand you can do this youself
by simply starting your vehicle and disconnecting your battery from
the positive side, if the vehicle stalls out tis generally means
that you alternator is either shot or on its way out. If the
vehicles continues to run, Your battery is dead. Simple way to
check on some vehicles if you have dual batteries, for example on
larger trucks, take it to one of the places listed above and have
them check it quickly