18650 3S Battery Case

thingiverse

This houses 3x 18650 battery case which can be wired in series or parallel. It seems to be higher quality than many others available widely. However, the contacts that you wire stick out the back. I didn't think taping up the balance board+contacts was a good look so I made a small case. It is important to solder things as flatly as possible as there isn't much room. This was built to fit inside the body of a 50s flashlight so the dimensions were constrained intentionally. You can probably get away with stretching it in whatever dimensions you want as long as you scale the lid accordingly. The battery case that I used can be found [here](https://www.amazon.com/gp/product/B07TRPV1ZJ) and [here](https://www.amazon.com/gp/product/B082VLCDYM) is the protection circuit.