I have two 11# propane
tanks in my tongue box and have room for several miscellaneous items as well. With a little re-arranging, you could easily fit two batteries and a single 11# tank.
I also have a 2000 honda generator
as well, but never take it with me anymore since adding solar
to the roof. I only wish that I'd seen Norm's posts about "new solar
install" before buying my panels. The company that made his panels looked like they would make custom sized panels. Two long narrrow panels would have been perfect on the raised section of the EggCamper