Generator Not charging Batteries

New batteries? Odds are they were connected incorrectly. Could be a number of things. Connected backwards, wire left off. Need more info.

Did this start immediately after the new batteries or was it happening before the new batteries?

My son set up my Solar panels about 4-5 weeks ago and he hooked it all up and it has been working fine keeping batteries charged. Then something happened and the batteries were down. The light on my awning switch was blinking for whatever reason. My husband changed a fuse out that was where the generator charges the battery ( I think) It is by the steps where the batteries are. I think that's when things got messed up. I think my husband did something and didn't get it back together correctly. I probably will have to take it to my son and let him look at it. I just thought I would see what I might learn on here. He didn't take the battery cables off the batteries. The only thing I know he did was take the cable off the Inverter. I don't know what he did down there in the compartment where that fuse is. It is a lone fuse. Anyway, Thanks.