custom battery bank (PROTOTYPES)

thingiverse

This is a custom-made battery case I created using parts from a product on Amazon.com. The product can be found here: https://www.amazon.com/Orcbee-Portable-5x18650-External/dp/B07L8Z8VPT/ref=sr_1_19?ie=UTF8&qid=1548968831&sr=8-19&keywords=diy+solar+power+bank. Two of these kits are required for the solar panels, which are wired in series with positive to positive and negative to negative connections. I have designed the case in four sizes, accommodating up to 40 cells. For those who want to review the design, I've included 3D files and STL files. To assemble the case, simply acquire the necessary parts, print out the case, and have hot glue on hand. I recommend using hot glue to fill gaps between batteries to prevent them from shifting around if individual cells or cell groups are being used. This is especially important when working with old power bank cells as they can weaken metal strips holding them together. When wiring the batteries, place the positive lead at the first cell closest to the board and the negative lead at the last cell farthest from the board. This will cause cells to charge from outside in, effectively acting as a crude balancing system.