Is this a good setup for charging my batteries.

Of course there is always the issue of expenses. A tight budget can crimp thoughts of more penels right away.

100W and a Morningstar 45 is an unbalanced situation--too much controller for a single module. You will definitely have expansion potential but why not either assess your power needs, now, and get an inexpensive controller to handle the single module or look long range and install the modules needed for your needs? Panel pricing is not going to get much lower than it is now so if you're set on the Morningstar 45, get thee some more modules.

Thanks for the reply, I have more time now and will provide some more details. My TT stays in the mountains all summer, my intent is to set up a single 100w panel and leave it hooked up all the time. My hopes are whenever I got to the camp (every 2-3 weeks) the batteries are fully charged. Down the road I want the ability to expand which is why I was thinking the Morning Star 45.

I am assuming that you will just haul the panel outside when you need it? If not, why not put more panel watts on the roof? That controller will handle 45amps, you could put a half dozen of those 100w panels up.......

There's some very knowledgeable folks here with install advice, and a permanent install, or even a temp/haul out one should have some circuit protection. If you get the temp sensor for the controller, your charge will be right on for the temp your battery is seeing. And.........the remote panel is really cool to put inside to monitor the charge and voltage, etc.

Yes, 1 panel over 4-7 days will charge the batteries after a trip, and a good charge controller like that one will be better than most plug in chargers at keeping the battery happy. But, if you want faster, you could always add more panels. BTW, you need to get a '12v' panel for that controller, I think.