Over two years and still nobody is making these to sell?
I accept that over time, alternative parts can be sourced that "may" improve some part, but...I feel this is very workable in its present form. I had hoped that maybe I could have started to produce these, at least until a real manufacturer began producing them (I have a full-time job).
I have an "open source" idea I haven't seen published yet, so I want to post it here and that way, anyone who wants to use the idea can point to the date on this post to show date of origin. I have contemplated a loose-cell box for quite a while. I am satisfied with the current state of this design, and Snath has encouraged me to produce it, and for anyone on ES to produce it. The one area where I have reservations is in...which way should the P-group cells face?
Should they alternate the positive ends of each P-group? (that way the connecting bus bars are compact and short. Or...should all the cells face the same way? Of course in the second configuration, the bus-bars will need to connect the top of one P-group to the bottom of the adjacent P-group. It would require the bus bars to have a shape like this:
xxxxxxx........ (dots are cells, X's are bus bar)
__..__x........
........x........
........x........
........x__..__
........xxxxxxx
Plastic forms in the cell separators would prevent the odd-shaped bus bars from being installed incorrectly by various means.
Whether the P-groups all face the same way, or alternate, my "Idea" is to have a nipple pressed into the bus bar where it faces the positive cathode button (just as Snath has done), but on the flat negative anode end, there is a hole in the center of the bus bar contact point, so a cell facing the wrong way will not make contact with the bus bar. The negative ends of the cells would have a contact with the bus bar that looks like a ring, provided by a larger diameter "button" pressed into the bus bar, and then a hole drilled into the middle). The positive end of the bus bar would have a small button that had the same diameter face as the positive button on the cell.
I would also color the insides of the P-group compartments so it would be even more obvious which way that cell-group should face. If assembled incorrectly, it would be an open circuit.
I know this "idea" needs some work, but I think it has some potential. Feel free to use this if it appeals to you.