I am getting ready to install solar panels on my RV. I would like to fuse the positive line from the solar panels to the charge controller but don't know what size fuse should be used. There is only about 15% difference between short circuit current and max power current for the panels I have. Suppose my nominal noon day current is 15 amps, if I fuse at 20 amps, a short in the positive line would not draw enough current to blow the fuse. If I fuse at 15 amps I might blow fuses every day. Am I missing something here? What should I use?