This installation was completed March of 2023. The owner of this travel trailer was looking for a way to keep the trailer batteries charged while in storage and to allow him to use the batteries for longer periods while boondocking before he had to use a generator to recharge them.  After discussing his needs, I put together a plan and an estimate for the implementation of that plan.  The customer accepted the plan and we scheduled an installation appointment.  The customer brought the trailer to me for the work and I completed the installation in a day.  I was able to complete the installation fairly quickly due to the basic nature of the job.  The panels were mounted on the roof, near the front of the trailer.  I penetrated the roof near the front cap of the trailer and brought the solar wiring down into a cabinet in the bedroom.  This trailer had a metal front cap that wrapped up onto the roof.  Initially I thought I might have to penetrate this metal overlap to get the solar wiring down into the interior cabinet cleanly.  After a bit of investigation, I found I could penetrate the roof above one of the ceiling light fixtures and then fish the solar wire over to above the cabinet and come down into the cabinet.  This prevented me from having to penetrate the metal cap overlap and worked well.  I then fished the wires from the cabinet into the pass through storage area under the bedroom.  The cabinet was full length from the ceiling to the pass through storage, so it hid the wires well.  The solar controller and circuit protection were mounted to the back wall of the pass through storage right below where the wires came down from the interior cabinet.  The output of the solar controller was wired along the roof of the pass through compartment and then penetrated out the front lower corner of the pass through and run directly to the batteries on the A-frame of the trailer.  The customer may eventually upgrade batteries, but for now is going to use the existing Interstate RV/Marine hybrid batteries.  I did add a Victron SmartShunt to make monitoring the batteries easy for the customer.  There was no room in the battery boxes for the SmartShunt.  I had a weather tight enclosure that I mounted to the front of the trailer near the A frame and mounted the SmartShunt inside that.  I ran all the DC negative connections that used to connect direct to the batteries into the enclosure and connected them to the load side of the shunt.  I then made a new cable that went from the battery side of the shunt to the negative terminal on the battery bank.