Fuses and circuit breakers are a must for a trouble free solar installation. The Big Baby Box below is intended to work with DC breakers allowing the installer to add reliable protection for a moderate cost. A common setup for the Big Baby Box is to provide switchable protection from the solar panel(s) to the charge controller and from the charge controller to the battery.
Battery mounted fuses are a simple and effective means of protecting your RV or Trailer from possible damage or loss due to an unexpected electrical failure. Very highly recommended!