This one might have to be filed under the fail column – at least for now. While throwing around some ideas for the next incarnation of DJ Big Gulp, I decided I needed to figure out how to make my own lithium ion battery packs. I bought a couple of INR18650s, some battery protection boards, and some nickel strips to connect them together. All I needed was the welder…
The showstopper
I thought it might be safer to try this rig out on some alkaline batteries before diving straight into the lithium ion. At first the welds seemed to be working, but after a hearing a pop and hissing sound accompanied by a weird smell, I decided it best to shut it down and go back to the drawing board. I thought the quick and dirty approach would get me the handful of welds that I needed, but it’s probably better to be safe than sorry when it comes to this stuff at least.
Ampere’s law in action
The current flowing through the weld creates a strong enough magnetic field to make the nearby nickel strips jump right off the table!
How to do it right
This guy built an awesome, configurable battery spot welder and has some great videos explaining the design process:
https://www.keenlab.de/index.php/portfolio-item/kweld/
