So I got a new battery after I had my old one tested at Auto Zone and they said it was bad. New battery is good and worked fine, but after three days I went to start it and I got nothing that time. It can't be the starter cuz that is new too, I had it put in some months back and didn't even run the car that much, plus I had my brother tap it while I tried to start car and still nothing. Anybody got any idea? Could it be the alternator?