I haven't found any bad cells (checking specific gravity), and the bank holds a charge (currently 12.70 after 24 hours), it is just when load is placed on it, the voltage drops, but voltage came right back after load was reduced to 12 amps. I may look for a battery load tester that does 6 volts, and see if I can find which battery(s) are not carry the load better than others.
I normally only use 1/3 the amp hours of the bank, so they are rarely discharged to 50%, and they are maintained by solar panels until the Montana got totaled and the battery bank removed around the first week of August.
The Equalize at high than normal voltage seems to help. Will do the other two pair when the sun comes out. It is worth a try, maybe I can get another year or two out of them. I have nothing to lose.
Here are the panels I got for the new Montana, and am using to do the equalizing. I think three will fit, and I plan to make tray under the Montana to store the forth one, which I can pull out and put in the Sun when camping in the shade.
