If you are just interested in keeping your batteries charged to run 12v
when dry camping look into a portable solar panel setup. Zamp is one company that provides several sizes that connect directly onto the battery posts. If you have the basic Parallax converter I would look into a 3 stage converter charger. Many of use have replaced our Parallax with a Progressive Dynamics swap out kit from Bestconverter. I'm not sure if the 2014 models have a 3 stage converter.
If you are interested in running a lot of AC powered devices while dry camping then you will need to do what others have done and install a combination converter/charger/inverter, run the right size cables from the panels on the roof etc as shown in the AM Solar website. You may want to get new batteries with more capacity, e.g. grp 27 or two 6v.
Look through the Electrical forums for what others have done. See what best fits your needs.