A 30 amp hour power bank I designed to fit inside of a .50 Steel ammo can.

I deliberately designed this to be contained entirely within the ammo can without any hole drilling to avoid compromising how waterproof the ammo can is.   There is sufficient room inside the can that a second 30 amp hour battery could be installed to create a 60 amp hour power bank.

I learned the hard way that the powerwerx charge controller has a parasitic load and the second switch must be wired to isolate the battery from the charge controller when not charging otherwise it will slowly drain the battery.

The junction box has the “tail” on it to limit movement and keep the wires from chafing as things shift around slightly.  The only thing holding the battery and the junction box inside the ammo can is gravity.  You coulld use two sided tape if you felt ambitious, but it was much easier to assemble outside the ammo can and then turn everything on its side and gently slide it in, rather than assemble it within.

The two safety switches are SPST, wiring this up is pretty straightforward.  See the included diagram.  You'll want male and female blade connectors.  Its fused with a simple automotive blade type fuse so it should be able to source replacements anywhere if it blows.

The 12v socket will power a small inverter.  The voltmeter isn't useful for telling how much battery power is left, but when it starts floating around 14.7 you're at a full charge.

Pictured is the 100 watt panel I use with it.