Hi,
Reconsider a fixed install--then solar will charge as you travel. It's kind of neat in my class c to observe the solar panels sending energy back to the chassis.
I have a generator on a rack and on a previous RV would use it to power the roof air while trundling down the road. That could have been a nice big fat converter instead.
I do have the same system available for use on my current Rv but haven't used it much--and never specifically for battery charging.
All that is needed is a safe way to connect the shore power cord to the generator.