I finished my solar project over the weekend. I have a 120 watt portable solar suitcase that runs to a Xantrex c35 inside the trailer. The hardest part was deciding what connectors to use, and how to run the wires.
What I did was make a waterproof junction box
that mounts on the trailer frame underneath the propane tanks. I have 10 gauge cables that run from the junction box to the charge controller, through the hole where the battery ground connects to the chassis. For the solar connections I used 1/4" stereo cables. Here why:
1) I already have a bunch of beefy stereo cables with different lengths. They are very flexible and I love the single input.
2) The female stereo connector fit perfectly into the hole of the junction box, as did the 30A toggle switch.
I metered the output at the solar panels and where the wires connect to the charge controller. No loss. No holes. A cheap DIY portable solution that works for me!