[Ronbo]

If you have a cut-off switch put a amp meter across it when off and check for leakage...

If you don't have one, get one. they're a must for vehicles that sit for days.

Since it's reading that low I can't imagine it's a load issue, sounds like a shorted cell in the battery. Since each cell is 2v you're reading is right on for a cell short.

This needs to be addressed since the alt is trying to essentialy charge a 10v battery to 12v so the rest of the cells will boil-off.