Hard part is done! Spending the money!
Get some coffee. This got long winded, even for me.
When do you spend more time in the cabin and need the most power from it? Summer, winter, or spring and fall. Ball park the Latitude from the internet, or get a buddy's GPS, to find a good mounting angle.
Good summer angle = Lat - 7 degrees
Spring and fall = Lat degrees
Wimter = Lat + 7 degrees
The panel must face South (I'd put it on the roof). The panel must have a mount, so there is nothing to restrict air circulation behind it for at least 6 or 8". This is important to prevent overheating.
Decide how mounting brackets will be fastened to the roof or whatever (For roofs, I thru bolt them with a 6x6" 3/4" plywood 'washer', metal washer, nylon insert lock nut, and a regular 'jam' nut.)
Now you can tackle the brackets. It takes less metal and stands closer to the roof when the PV is horizontal. Remember to figure roof slope in the finished angle. A weld shop with a bender can make them in a few minutes. Most look like a distorted "A" on stilts. Some people report good results with slotted angle iron commonly used for garage door instalation, I think it is kind of too weak, but it only takes a bunch of nuts and bolts and a hack saw...
Maybe the panel comes with factory wire. Probably not.
I use 12-2 w/g UF, the GREY type (all of the UF is sunlight resistant, but the grey is more resistant), connected to the PV box with a water tight strain relief. It's a 'romex' connecter with a rubber plug having a hole the size and shape of 12-2 wire, a big cap nut tightens the rubber around the wire.
I strip about 10" of the outer insulation, slide the strain relief down, fold the ground wire back 1/2" and wrap it around the wire so it can't pull out. The wire goes out the bottom of the box when it's mounted, and I like the PV box on the East end. If the panel has quick connects, crimp on the right size, then solder them with electrical solder (crimp ons don't work well with solid wire).
If the PV box has screws its easier. Bend them into a clock wise hook and tighten the screw, let it sit over night, tighten them again (suprising how much more)
I use Black for negative, white for positive. To avoid corrosion problems put some electrical grease on the terminals before and after they are connected (GB brand Ox-Gaurd is the commonly available type).
Opinion differs on sealing the box. Totaly sealed means a tiny leak will allow condensation and corrosion. Some people don't seal them at all to allow the moisture to escape. I seal the top and sides, but not the bottom, with silicone.
Bolt it up there. With luck, there is little or no twist to the panel sitting in place. On a roof getting the wire in takes creativity. Sometimes you can lift a shingle, drill 1/2" hole under it, feed in the wire, silicone it up, put a brick on it til the silicone cures.
Get the wire to the controller. Staple it every 3', not to tight. Leave an extra foot at the controller for future use. Remove 6" of grey insulation, strip 1/2" from the wires. I cut off the ground wire. Grease up the stripped wire and controller screws. Attach the wires.
DO NOT LET THE PV WIRES SHORT WHEN CONNECTED TO THE CONTROLLER. IT WILL DAMAGE THE CONTROLLER! This includes the use of ammeters across the PV terminals!
Use stranded wire from the controller to the battery. 10 or 12 ga. The controller end should have a crip on fork terminal (I solder them too). Grease them up, install. The battery end is up to you. The red and green felt washers battery washers work well against corrosion. The controller is temperature compensated, so it should be in with the battery.
Morningstar says to connect the battery, then the PV. Then they say it dosen't matter.
I left out fuses until now. Most people believe a fuse between the controller and PV should be there, and one between the controller and battery, rated 1.4X the panels output amps. Auto blade fuses in pigtails are a good choice, easy to see if it failed and the local '7-11' has fuses. I have never seen one blow in a small system.
Grounding is sure to get some replies! If you chose to ground the system you must use a DC lightning arrester or you have an expensive lightning magnet!
You could get a little fancier. Like a fuse distribution block handling all the fuses, making only one set of clamps to the battery. It would take some soldering skills.
I have some pic's if you need them. The Wife would have to get them from the camera card to here when she has time. Solar powering the camera is easier than working it.
Forgive the typos
G-