Hi Jim. I would call Troy at Liberty. My understanding is limited, but I was told the inverters were working together, one being a back up to the other. When mine charge they charge at about the same load rate which indicates to me both are running & sharing the output charge. If you turn one off the other one will pick up the charging load. The 4 batteries I have are in parralell / Series so they are all connected to both Invertor/chargers.