ok, i remembered i had a digital oil pressure gauge that defaults to volts when there is no signal to the wire, so i used that as a gauge
the battery shows 12.0 with the engine off
12.6 with it idling, and 12.8 with it revving
i tightened the belt and that didnt seem to do much, it did not change the readings
just to be sure, i hooked it up to a trickle charger