My car is not charging the battery, the alternator is good. What else can it be?

 

the alternator.

maybe one of the cables on it are loose.


also might have your battery tested.

 

Try cleaning your grounds. Best place to start is the connection between the negative battery terminal and the engine. Remove this ground to the engine and clean it with sand paper. If your battery is not grounded properly, it won't charge to the correct voltage. In fact you should replace the negative battery cable. Battery cables are made of disimilar metals. Poor grounds cause other peculiar electrical problems.