My car has been sitting for about 3 months. I go out today to take it for a spin and it won't start. So I charge it up, starts right up.

As I'm driving my radio keeps cutting off when the bass or volume gets high. It also cuts off when in idle if I turn my headlights on.

Also, after about 30 minutes of driving I park her back at home, turn off the ignition and try to restart and it barely gives any juice to the radio, lights or anything then everything fades... then.... nothing.

I figure it's gotta be one of the two but I have no clue what each one is responsible for.

TIA!