My car battery has died twice. Don't know if the alternator is bad or something wrong with the charging system.

Battery light comes on when:

When I come to a stop(low rpms) but goes away when I start driving or rev the engine.

Also when I turn on headlights and then roll down the power windows the headlights go dim(also rpms drop for a little but then go up).

And sometimes when I accelerate battery light comes on.

What could be wrong? All anwsers will be appreciated.

Thanks

 

I experienced a similar problem on my car, it may be a lose cable on the alternator, it may be the alternator starting to go bad. Test it to see the voltage you're getting out of it, or just take it to an auto store that could test it for you at no charge.