I am starting to find interest in more med/long range RC, and Li-ion setups. Found the thread in Endless Sphere for the JP Spot Welder where the designer open sourced his creation after selling them for a long time. For the electrodes, I came upon an Instructables for a pair of Pen-style electrodes made from brass (I used aluminum) tubes and drill collets. I only have a rudimentary knowledge of electronics & circuitry, yet I found this build to be fun, educational, not that difficult to build.
I'm just doing this as a fun, relatively inexpensive project, I'm not mass producing battery packs for an ebike or ecar. It's more than enough for the hobbyist, and probably good enough for a pack-maker that wants to make $. Whether it's cheaper than buying a low end commercial battery spot welder, I do not know.
The end result is an adjustable, duel pulse battery spot welder.

All the information is located in the following:

- JP Spot Welder info
- Pen-Style Electrodes

The PC boards can be fabricated from an online vendor such as: JLCPCB
Just upload the board files found from the Endless-sphere thread. Cost is like $5 for 5 boards including shipping. Seriously don't know how they make money.

Components can be purchased from Mouser or DigiKey. Rest of parts can be found on Ebay.

Here's a short video of it in action: JP Spot welder w/pen electrodes...Continue Reading