Fix an old powerbank with 18650 Li-Ion batteries

Let's get our hand dirty and fix an old power bank. I got this thing a few years ago but recently it died. Li-Ion 18650 cells inside just died and now it even can not do a full charge of a smartphone.
What we will do over here:

  • get this thing apart
  • solder together 3 18650 batteries I got for cheap from disassembled power tools battery packs
  • I will be coughing after inhaling too much of soldering acid fumes
  • have a nice talk about a zombie apocalypse, nuclear holocaust, communism and Kapton tape
  • get things done!

How to solder 18650 Li-Ion batteries

All 18650 Li-Ion batteries are hard to solder. Well, not only 18650 but all nickel plated metal elements can be very hard to solder. But only if you do not have the proper tools. In this case, proper flux: soldering acid. Forget about sanding, scratching and other voodoo. Just watch the video, it will clearly show what I have in mind!

No more sanding or scratching of 18650 Li-Ion connectors. A drop of soldering acid sill all that you need!

Getting started with 18650 Li-Ion batteries

18650 Lithium-Ion batteries are the workhorse of modern consumer (and not only consumer) technology. If you have anything that is battery operated and there is a "Li-Ion" mark anywhere on it, probably it is powered by 18650 Li-Ion battery. Laptop batteries, cordless drills, cordless tools, e-cigarettes. All of them (probably) have 18650 cells inside.

In this video, I will just go with the basics of 18650 cells. Dimensions, protected / not protected difference, weight and so on. Expect more in the future!