Just finished mounting my battery to the rear of my el camino, and have noticed at night, with every thing on that the volt guage is showing only 11 1/2 volts. I have a 100 amp single wire voltage altenator, and its always showed 12 volts or more on the guage. I ran the single wire off the altenator, back to the battery with a 10 guage wire, to the + post, am i running to heavy a wire or is it something else. I've cut out my night driving for fear the battery will go dead! Any ideas?