Alternator Gauge needle leaning to the "PLUS" side?

Went to leave the house (engine warm) got to the end of the driveway and the engine stopped like I had turned the key off? Headlights were on, defroster fan on high and wipers on. Turned everything off and turned her over and took right off. Drove around the driveway all is well. Drove 10 miles to town and engine seemed to be missing while setting at a red light. I turned the headlights off and the defroster off and the engine straightened out? Noticed the needle on the alternator gauge leaning toward the plus side. Need a new battery or do I have an alternator getting ready to die? Guess I'll drive the Corolla to work tomorrow. :(