Do-it-yourself powerbank for 21700 batteries

#powerbank #diy #gadgets
The powerbank uses two 21700 lithium ion batteries sourced and welded together by the user. It looks good, compact, and performs well. However, as total amount of mAh output depends on the batteries inside, so wise choice of a decent pair is a must. In short, case, good, batteries, bad.
DIY kit from Aliexpress:
www.aliexpress.com/item/1005004908730889.html
Spot welder:
www.aliexpress...