Here's the finished product:
Interior:
Its set up for trickle charging with a Battery Tender Plus at home, with its charging pigtail hanging (sealed with a dust cap when not in use) out one of the over-hanging parts of the lid and secured with a zip tie so the entire wire won't fall out of the box if it snags on something. Main features are the Seasense 12v sockets (I can't recommend them, they're slightly bigger than 1" in diameter, meaning lots of hand-trimming to install), Bussman fuse block, a neutral bar from Home Depot re-purposed into my ground block, a random $8 battery box & 3M DPST switches from Walmart, 10 and 14 gauge wire and 0.250" connectors. I really lucked out on the 3M switches, I'd originally planned on putting them on top of the box, but my idea on where to place the outlets just happened to clear the bezels.
Total cost was $268 + tax for the pack itself, a little higher than I had thought it would cost when I set out since I did not have many of the basics like a battery charger, stranded wire, fuses, terminal connectors, etc, but it will be worth it the first time we have light when the power is out.
I'm still awaiting the trouble lights I ordered, so at the moment I just have two low-noise computer fans to play with.
Future expansion include a wiring harness for an inverter, a circuit breaker to kill the entire output from the positive side of the battery (right now it relies on the four circuits all being fused at 5amp, the 10ga line is good for 100amp per my understanding, so there's no way I can over-draw it in normal use), fast 120v (no point running my junky, 30+ year-old, oil-burning generator to trickle-charge a battery) and alternator charging.
When we finally build our trailer, most of the parts should be reusable, or we may keep this one for home use and build a new system for the trailer.
