Problem with conext sw 2524. Possible relay

[Pass_lake]

I have two sw 2524 inverters. When the sun goes down, the inverter switches to battery until the batteries drain and then the unit shuts off, around 2;30 or 3am. I can reset it and the batteries charge enough to get through to the morning (usually). When the sun comes up the system works normally. 

I have to shut off all the load except the fridge and freezer before sundown to last until 2am.

Does this sound like a problem with the relay?