Powerbank revived

Years ago, my nephew William gave me a powerbank that has a wobbly micro-usb connector. The powerbank was used for the Robot Counter project and left in the Robot for some time. Recently, I took it out to recharge but when I pluggin a USB cable, the micro-usb connector fell off completely. I remembered that once I purchased some powerbank modules (left image below) and so I opened up the powerbank and replaced the old module with the new one (right image below).

The powerbank module was purchased from Aliexpress at about AUD$1 dollar each. It has three input charging ports: USB-C, Micro-USB, and Lightening port on the side. It has two USB-A output ports and as shown on its LED screen, they seem to support QC and 2.4 A output.  This powerbank is quite old from 2013 but its 3.7v lithium polymer batteries seem to be still quite good. There are 4 li-po batteries and I am not sure if they have any battery charging manage system chip or are just connected in parallel. Because it has two wires (red: positive, black: negative) so just simply solder them onto the new module and it works. I then plugged in a USB-C cable and it starts to charge from 0% (right image above).

Then I thought that I should design an enclosure for it but with good luck, I found someone has already done it and shared on Thingiverse, which is exactly designed for the same powerbank I have. The original case though, was designed for fitting 6 x 18650 batteries at 143.75 mm in length.  Because my li-po batteries are slightly longer so I need to tinker the case to be 150 mm long.  This tinker case can be found in my TinkerCad project.

With my Creality K1C printer, the case took about 1.5 hours, the front cover took about 20 minutes, and the small button took about 2.5 minutes to printer.  After inserting the batteries and the module, the cover is then super glued to the case. The final product is a revived powerbank, useful and feeling quite satisfactory. :-)

By Andy on 31-05-2025