Running 24V system with 12x 2V 1500ah Mastervolt traction gel batteries, all on their side. Batteries are connected via connector plates Inherited this ESS, it's located under the house on clay soil and some structural plywood. 100kg each, not surprisingly the ground has settled a bit over the last two years and the top two middle batteries have slid back. The terminal connection held strong and the plate/terminals have been pulled out a couple of centimeters.
Voltage on the other 10 are all reading fine and balanced, but the two damaged ones were less than 1V each. They've obviously discharged but haven't been able to charge up to the same level as the rest of the system. Now the system sits at about 26V with the sun on and balances out at about 20.5V. I've disconnected the two damaged batteries and there is no difference in the performance of the system.
The question: best way to fix? Seems like battery balancers (active) would take too long and likely mess the other batteries up. My current plan is to run a 20V system until the working 10 discharge down, reconnect damaged batteries and charge up, disconnect damage batteries and discharge the 10, on and on until the 2 damaged ones are back at an acceptable level.
Another idea was to try and trickle charge the 2 batteries separate to the rest of the system, but nothing in the market to charge 2V or 4V systems, and I'm worried that hooking up to a trickle charge solar panel would be more trouble than it's worth? Not going to move them out (it's very, very hard and inaccessible) but could get some looong wires from a small panel. Would monitor this rather than using an MPP controller.
Anybody with experience on this one?
