Yep—Yeah, love those honda 2000's....At one point I owned 11 of them for my business.
I modified the fuel caps to run off 6 gallon marine tanks and ran them in parallel....unfortunately, I didn't think to take one along on the trip I described..
You do know you can get a set of cables and go straight off the generators 12v ports for charging ? Off the top of my head, I think it's an 8A output...
have larger tank and second generator for paralleling them when needed —but only need in summer for air conditioner