[Festus2]

You can use a stand-alone battery charger that is connected directly to your batteries without harming the rest of the circuitry in your unit. The charger can simply be plugged into your campground power pedestal or you can plug it into a 110v outlet of your RV.
Solar panels aren't all that complicated but remember they only work efficiently when the sun is shining. They do produce some amps on a cloudy, overcast day but at a very reduced rate. I have a single 85w solar panel and use it to maintain the charge on my 6v batteries. On a clear, sunny day, it will crank out between 6-8 amps - enough to maintain the batteries. If they were to run down, this 85w solar panel would not be enough to bring them back up to charge in a reasonable amount of time. That is why I carry a generator with me -- works rain or shine!