The following is a battery box build I wanted for field operations, with overall dimensions at 12in x 6in x 7in and the whole unit is about 12lbs, I started with a fairly good-sized ammo box I acquired at a hamfest I cannot even remember how long ago. My first attempt was with a salvaged lead-acid UPS battery, but I found it too heavy to be practical, and the cells were not in great shape. I did some reading on Lithium Iron Phosphate and decided to give that a try, especially since a 20aH was just about the right dimensions. The very first iteration was with the triple bulkhead mount outlets similar to Powerwerx, but definitely a Chinese knock-off. When I bought that panel a few years ago, it did not have an Anderson PowerPole module, but I was able to locate a 3D Print STL file and printed my own.