You want to have solar panels to charge your RV batteries in order to have electricity power without being dependent on hookups but you do not know exactly which one suite your needs best. The best way to find out your exact electricity needs is to actually measure it. That said, the second best way is to follow the following golden rules that will assist you determine how many amp-hours you consume which will help you to decide which solar panels you need in your recreational vehicle.
For RV trailers and fifth wheels, a 65 watt solar panel for the basic battery maintenance is minimum requirement.
For RV Motorhomes, a 100 watt solar panel for the basic battery maintenance is minimum requirement.
200 amp-hours of battery storage capacity with about 200 (range is 150-250) watts solar panels are suitable for low electricity consumers.
400 amp-hours of battery storage capacity with about 400 (range is 300-500) watts solar panels are suitable for average electricity consumers.
600 amp-hours of battery storage capacity with about 600 (range is 500-750) watts solar panels are suitable for average electricity consumers.
The good thing with solar panels is that you can start small. If you are not sure how much electricity you consume in a regular day then start with the minimum that you are confidence with and later on if you see that you need more, you can add more solar panels to harness more solar power from your RV solar panels.