i have a off-grid installation with: 2x250Ah gel batteries in seriel configuration, 1 multiplus compact 24/1200/25 inverter, cerbo gx, MS sunsaver mppt. My installation does not have load peaks but a constant load of around 70Wh
normally the batteries keep at full charge and battery voltage use to be at 25V but when I have more than 2 continous cloudy days when solar panels can not charge batteries, i experience the following behaviour. As load is constant the battery voltage is decreasing slowly and when after 2 days reach 22'4V, then drops almost instantly 2 volts, from 22'4 to 20'4, and then continue decreassing slowly as before.
As the batteries are only 6 momths old, i think that the issue is related with inverter configuration.
Any idea about the root cause of this behaviour and solution?
thanks