out what size charge controller for solar panels.??

carl2591,

Think of it this way. The existing controller can do 20 amps output at a nominal 12 volts. That is only 240 watts. The panels are simply too high a capacity to be efficiently used with such a controller.

If the RV battery bank were changed to 24 volts, then the controller could handle just one of the two panels.

Here is an article to perhaps help: https://freecampsites.net/adding-solar/