its the alternator.
when its at the point you described that means that its about to die completely.
get it fixed immediately (tonight) or your going to be stranded somewhere.
they are easy to install your self on most cars. all you need is a socket wrench set and you will save your self 50 to a hundge in labor.
Oddly enough, I just drove home from work (New Haven to Wallingford) without a problem. I\'m still taking it to the mechanic, obviously, but at least my car isn\'t sitting on the side of 91 with smoke coming out of the hood. Hopefully, unless it\'s something really small like a blown fuse, it\'s the alternator, which sounds cheap and simple enough have repaired.