Hardware:

4x M3 Screws are recommended for securing the back cover, but hot glue will also work fine.

Use some hot glue and foam to hold the circuit board and batteries in place.

Circuit Board:

For the charger and USB outputs I used a rather cheap circuit board from ebay.

However if you want to use a different board I have provided the STEP files for modification.

Seller One, Seller Two, Seller Three

Batteries:

The batteries are the most expensive part of this project. Make sure you get them from a reputable seller or if you reclaim them from somewhere, like a laptop, make sure they are in good enough condition.

Where I got my batteries from: IMR Batteries

Attaching the batteries can be done two ways, soldering and spot welding. If you are going to solder the batteries together with a strip of wire be very fast to not overheat the cells.

When handing the batteries make sure you have a plan if things go wrong and make sure nothing ever shorts out.

I am not responsible for any harm or issues that your battery pack may have caused