Had problems with the windless and burnt out a motor
on it... found out that the voltage drop from the house bank to the windless was great so we mounted another battery under the windless in the line with the house bank.. gave us a larger bank and high voltage at the windless..
About your batteries, you have to treat them just like one of your kids
and know everything possible about them, the algorithms of the batterys, how they charge, the fully charged point and the 50% area.. (ours, lifeline AGM
4ds) are charged at a high rate but are fully charged at 12.8 volts, and are at 50% when at 12.2 volts.
You will gain and lose a "TOP" charge or "SURFACE" charge very rapidly.. so what you might see is 14 volts after charging, will drop to a low charge after 24 hours... you've lost
the surface charge..
To check the batteries, take each one independantly off the system, charge it and let it set, and see where it lies after 24 hours.. Your batteries will only charge to the weekest link in the chain and if you have a problem in "one" battery, it will show in the whole system.. Checking each one independantly is about the simplest and cheepest wat to start.