I think my alternator is done. The voltage gauge in the car keeps getting a little lower every day, and just started dipping into the red. Is there a chance It could be my battery?

 

Well, if you let it go too long. It could both be your alternator and battery. Get a voltage meter, and test the batter when the car is running. If it isn't above 12, then the alternator isn't charging. But there can be a few reasons for that, blown alternator relay fuse, make sure to check the wires coming off the alternator. You could replace both the alternator and the battery, and still have problems.

 

Most likely cause would be the alternator, I would throw a new one in there, before you end up like me, driving home with no lights at night time, hoping that the gauge that reads almost zero is lying, and that the computer will have enough juice to get me home.