Join Date: Dec 2018
Location: Tasmania & Europe
My Motorhome: Hymer Classic B584
Thanked 11 Times in 11 Posts
You might want to calculate how much power the air con is going to use run via inverter off batteries (you probably already have). It's not going to last very long. Depending what time of year (and what latitude) you intend travelling, my thoughts are the more solar the better (payload permitting).
I'd be thinking if it gets so hot you want air con, find a site with EHU that can run it. However I suppose if it is that hot, it's likely also sunny, so with enough solar and batteries it might work.
For your question - you can't overload batteries with solar. If they produce excess it just doesn't get used. That's one function of the controller. One problem is you have to put the van in sun for the solar which makes it more hot inside, so you need more air con. I have thought an option would be portable panels (as well as the roof mounted) so you could park in the shade if desired, but still get optimal solar.