I am in the works of trying to buy a ~24' enclosed trailer for multi use. One of the things I will use it for is camping in after unloading all the toys. They come with lights inside as is but only run if plugged into a vehicle. My plan is to upgrade to LED (if it does not already have them) and install a couple of large batteries inside. I want to be able to run the lights, charge small things like cell phones, and run a couple of 6" 12v fans on those hot nights. For the most part during the day nothing is going to be running. My question is how big of solar set up do I need and what is the most cost effective way to do it? I have seen several solar sites but many of them are several years old and much has changed since then. Also I see a lot of "consumption" tables based on use just like a generator which I am very familiar with. I can not find quite what fits my needs. I am trying to get and idea of what Watt size panel would be needed to put a decent charge on 2 large batteries each day.