1985 toyota pickup charge anomaly ?

So for some reason my 2 month old battery died the other day. Assuming there's a short somewhere within the elec system. Anyway, I charged it and my charge light is still on. Now, my charge meter on my dash goes up to 18 I think and at full charge it used to be right below that . Now, whether i have my lights on or not, the meter is almost at halfway. So here's the weird thing....i went to buy something to eat last night awhile in the drive thru i moved up the line and had reved my engine pretty high....all of a sudden, the charge light when off and my Meter went all the way up!! As soon as i drove a couple of feet and turned the corner, the light came back on and the meter went back down. What's causing this and how did it temporarily get fixed when i revved my engine? Please help :( terminals are brand new as well.