There should be a charge controller wired into it somewhere, we put ours on a wall where it can be easily seen, has a bunch of little
lights on it and sometimes they come with a dial when it reaches it's limit it shuts the charge off so it does not over charge the
battery. Who ever
sold you this Trailer should of filled you in on it all.
To get the wire down to the
battery, u never want to drill or cut a hole into the trailer, if you do then your open to water problems. The easiest way is down the
Fridge vent, bathroom vent or any vent that is already there.
Solar power is just like
Electrical power going into your home, u cannot see it unless you get a shock then u only know it is working when u turn a
light on or run a item that needs power.
Stude