[CREWZIN]

Quite possibly your alternator is going bad, but that's only a guess. Any of the decent auto stores (Auto Zone, Pep Boys etc.) will be able to hook your charging system up and pinpoint the exact problem.

Follow the PT to the auto store with a good vehicle with jumper cables (just in case). If you don't want to do that, you can just take the battery out and take that to the store. That will at least tell you if the battery is still good (bad cell?) and if it's good, more extensive testing has to be done.