These PCBs were designed to connect and mechanically put together 18650 Li-Ion cells in to big battery packs. This exact design is meant for 12s9p battery pack but the design could be adjusted for different pack sizes and cell types (21700 for example). Cells are connected to the boards using thin tin plated copper wire which also acts as a fuse for individual cells, thickness of this wire needs to be adjusted to maximum amp draw of the battery cells used.

I decided to build this project to be able to use the pile of 18650 cells I have. The battery pack will be used to charge drone batteries, power my trips to the nature, act as a backup power source in case of power outage.

This project is still a work in progress, that's why I don't recommend building this to anyone until the design is finished and tested.