I don't have layouts but can try to do a drawing of how I wired it. Here's a picture of the internals that I wired up for a test run. I've since added loom to the bare wires and paired some of them up together using cable ties to clean up the aesthetics and make it slightly easier to add/remove things. I also plan on labeling wires in the future just to make it easy to identify and trace faults etc.
I used a coupon and got a great deal on the Renogy 20A DC-DC charger and actually bought it before I decided to pursue this particular battery box design. I paid around $100 for it so it offered great value that I didn't want to pass on. In hindsight, I'd probably not go for it again because it is big and loud though with its DIP switches I can set LiFePO4 voltage anywhere between 14.2 and 14.6 and an ignition wire allows me to not worry about the smart voltage sense etc. I have it wired to a switch and I turn it on when I want to use DC-DC instead of it always turning on with the ignition. Right now it is doing its job, but I may replace it at a later date with a Victron 30 Amp in case I need to utilize the space for something else.
If you are interested in an integrated dc-dc charger within this form factor, then hit up
@cruxarche as he has installed an 18 Amp Victron smart DC-DC charger inside the very same Milwaukee packout box and it just fits with almost the same components that I've used. We both needed a similar solution around the same time and build our systems together over private messages on this froum and via text..lol..His set up came out really nice and he used the same battery and has an MPPT and DC-DC charger, Anderson powerpole and SB-50 connectors and USB charging etc.
The Milwaukee packout family of tool boxes and other hardware comes with an integrated lockable feet design that lock into a
mounting plate that they also sell. These can be horizontally or vertically mounted and tool boxes can be secured on them up to the weight rating of these boxes . It is a very sturdy latch and folks have demonstrated this by
hanging off of it. The problem with the Milwaukee branded mounting plates is that they only come in a particular size that accommodates two of these packout tool boxes (this is the medium sized / 10" tool box) side by side. Since I only had one and didn't have use for the second, I wanted to see if I could get a "half plate" instead that has just large enough a footprint to accommodate one of these boxes. This would save some space. Milwaukee doesn't make a half plate. I did a bit of digging and found that there is an Instagram user ("rainbowlanespeed") who sells half-plates in both steel and aluminum. You can see the half plate that I chose (steel) in the second picture, and it attached to my drawer system where the aux battery will live right next to my fridge. I like the plate as it is one less thing that I have to worry about strapping down.
Yeah I can totally see me trying that out in the near-mid term and trying to see if I can squeeze in more capacity in the same form factor. For now though this is more than plenty for our needs. The 50 Ah Battle Born can discharge at 60 A continuous but I think BB still holds the 0.5C recommendation for most optimal charging with longevity in mind. I currently use a 20A charger but the max that I'll ever think of putting into mine is 30A which should be fine. 30A is also the upper limit of what my current vehicle wiring and alternator will comfortably handle given everything else that I've used so its probably a good max for me at the moment. Coming from LA though these things are nearly magical in terms of how fast they are capable of charging. I currently have a 10 A AC-DC charger but will probably upgrade to a 25 or 30 Amp option for fast Ac charging when plugged in. We don't often plug into a camp site so rapid AC-DC charging when on the go is not that appealing compared to DC-DC and solar charging.
everything 
I'd be ever grateful if you'd post a complete list of components as well as any suggestions or ideas on if/how you could improve upon it as I want to build one of these to use with my trucks when I'm offroading/camping/overlanding. I've used dual battery systems in the past and had been thinking about going with one in my Jeep but that won't help me with my other truck so a portable battery box with solar charging capabilities is ideal (and it may be less or as costly but with greater functionality).
www.duracellpower.com
