Spent the weekend wiring up my first little off-grid setup and it actually works

That feeling when the inverter clicks on for the first time never gets old. I did mine on a sheet of plywood hung off the garage studs about a year back and it's still running fine, so a board on the wall is plenty good enough for a small setup. One thing I'd suggest while it's still fresh: take a photo of the wiring behind everything before you zip-tie it down. I skipped that and when a breaker tripped six months later I had to untie half the loom just to trace where a wire went. Also nice job on the fuses. My first build had none and I got lucky nothing cooked. For the panel mounting, measure twice on the roof penetrations. I used lag bolts through shingles with some roofing sealant on a simple tilt frame and it's held through two winters. I started with a single panel on a windowsill too, just enough to keep a battery topped up and run the router during outages. It grew fast once you start adding loads, so leave yourself some empty space on that board now. The breaker labels matter more than you'd think. I ended up with a label maker after a season of guessing which switch killed the lights.

I went the shelf route instead of a wall board. Mine sits on an old bookshelf in the basement with each piece on its own shelf level, batteries on the bottom. The one thing I learned the hard way is that heat matters more than looks. My first battery bank lived next to the water heater and the capacity dropped noticeably over one summer. Moved everthing to the cool side of the basement and it held up fine after that. So if your garage gets hot in July, think about where the tote sits relative to the sun beating on that wall. On the wiring, I used lugs I crimped myself with a cheap hammer crimper from an electrical supply place, and two of them worked loose over a year. If you ever smell anything warm near the busbars, check the crimps before anything else. For the panel mounting, I waited two years before putting mine on the roof and honestly the ground mount rack I finally built from fence rail is easier for cleaning snow and adjusting tilt. You can walk up to it instead of dragging a ladder out every time.

I have to push back on the lag bolts through shingles advice from earlier. Driving a big fastener through shingles and smearing sealant over it is asking for a leak, the hole opens up as the wood moves with the seasons and the sealant cracks. A proper flashing kit or a stand off frame mounted to the fascia or ground rack costs a bit more but you are not chasing water stains inside later. Two winters is not a real test, roofs fail slow.

Running the lamp and fan all evening is exactly how I tested mine too. One thing I'd add: check your charge controller settings before you hook up more panels. Mine came defaulted to sealed lead acid and I was running lithium, bulk voltage was way off until I fixed it. Took two minutes with the manual and made a big difference in charge time.

Congrats on getting it off the kitchen table, that's half the battle right there. Curious what you're running for batteries in that tote, I started with a couple of small ones in a milk crate myself. Also don't skip the fusing on the battery side, that's the one spot where a short can get ugly fast.

Update: checked the controller menu after reading that reply about default settings, and sure enough it was set wrong for my batteries. Switched it over, easy fix. The panel mounting is still the holdup though. For those arguing roof mounts vs flashing kits, what did you actualy end up using, and did it hold up over a winter?