One other thing. On mine, I have two sets of cables leaving the battery area. One set goes to the inverter, and the other set goes to the rest of the trailer's 12 volt system, including the charger. Those two pairs of cables need to be connected together at the batteries.
2014 Cedar Creek 36CKTS Explorer
Xantrex Freedom SW3012 inverter/charger
2009 Silverado 2500HD Duramax Crew Cab short box
Demco Glide Ride pin box
Demco Hijacker Autoslide 18K hitch