um i'm sure you did this, but make sure that your wires are connected to the alternator. it sounds like it drove for 4 miles on the power of your battery which isn't enough voltage... which would make your car run like shit.

i don't understand the sentence: "Popped the hood and the battery hod gotten disconnected, which made me think alternator."

does that mean one of the terminals on your battery had gotten loose so you assumed your alternator was bad? what?