Ryobi Li-Ion Battery Pack

While working on my Lack project my 10 year old Ryobi batteries which had been rebuilt a couple times just weren't cutting it anymore... So I went looking for a better option...

3D printer - Check...
ton of 18650 cells - Check...

I found a couple reference models on thingyverse that I've used before (like enif's battery case design ideas, and leaning on Simhopp's modeling work on the case I redrew it, modified it and built a couple extra parts to suit my needs...

In the end, this pack is ~50% the weight of a Ryobi NiCad case (600g vs 1kg) and has almost 4x the capacity (~1200mah NiCad vs ~5000mah (2x2500mah) LiIon). Images of the scale included, I didn't know it was going to be this light... (on the downside, my large drill now can tip it over lol, might have to add weight.

Let me state this here first:
1. LITHIUM ION BATTERIES CAN BE VERY DANGEROUS! Improper charging, accidental shorting of cables, etc... can cause them to catch fire and/or explode
2. If your not confid