Dual 18650 and 20700 battery charger

thingiverse

I designed these chargers because my old Nitecore stopped charging one side completely. You'll need to purchase the TP4056 board from Amazon or eBay, which I acquired from this link: https://www.amazon.com/gp/product/B01DRT4PWY/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1. Additionally, you will require some thin wire that fits perfectly in the grooves on the bottom of the board, a few standard paperclips, and 8 male header pins. To begin, bend the paperclips as shown in the pictures. Notice I intentionally leave one leg longer than the other. Next, slide the paperclips into their designated slots. Then, bend the longer leg towards the other leg until they touch and trim any excess. This will serve as your solder point. Solder one end of the wire to the paperclip and the other end to the short side of the header pin. After that, slide the header pin into its correct hole. Repeat this process for all remaining solder connections. Keep in mind that the top slots are reserved for connecting the two boards together and will only have a header pin soldered to both sides of the wire. Finally, place the boards with the pins sticking through the holes in the boards and solder the pins to the boards. The TP4056 can deliver a maximum of 1 amp per board, which means that if you want to fully utilize its capability, use a 2-amp charger. JanM created a lid for the 18650 charger board, available here: https://www.thingiverse.com/thing:2760988