Coming back from work 1 night the battery light came on and the car started losing power but fortunately I made it home. After that it wont start so i charged the battery and let it stand idol and i noticed 1 of the belts wasn't rotating. What i want to know is which belt hinders the car from starting or kills the battery or alternator. Why would the battery light come on if the battery wasn't really dead or dying? Could there be another problem?

the belt that drives the alternator is broke. the alternator charges the battery. If it is not charging the battery, as the battery discharges it becomes discharged and is "dead" and won't start the car.

Replacing the belt will fix the problem