Adding batteries to Thor Majestic 23A

Yes, link above provides very good info on X rentals, if you haven't read it yet. If you can't find anything that you like, check out the link below. While I like the concept I refuse to pay what they want for basically a battery holder. We start genny when battery gets low. Which is very seldom. If we stay'd longer at a place then I would add another battery. But for now 1 battery is good enough for us.

http://www.torklift.com/index.php/products/auxiliary-battery-storage/hiddenpower