18650 Powerbank Battery

Diy portable 18650 battery bank. Battery arranged in a 1s4p or 1s8p arrangement. 18650 cells were recycled from old laptop batteries, however, can be bought new. The battery bank module used was the 5V 2A 18650 Power Bank Charging Module and can be bought from many sellers on Aliexpress (https://www.aliexpress.com/item/32976709704.html?spm=a2g0s.9042311.0.0.37684c4dUeks6t). The battery can be soldered in parallel leaving an output of 4.1V and placed in the body of the case. The button will then need to be secured in the case, then the insert (with the battery bank module glued to it) can be soldered to the battery then inserted into the body. It is recommended to balance each cell before use, this is essential if you are recycling batteries, to do so I recommend the OPUS BT-C3100 smart battery charger (In Australia can be bought from lanplus.com). Including the filament, the full power bank cost came to $3 and the small battery has a capacity of 9350mAh, the large battery has a capacity of 24500mAh.