So it begins...... Battery spot welder

[sternwake]

I tried 0.10 under 0.15mm copper under 0.5mm SS.

It welded, but pull off strength was not all that great.

The 0.10 welded to strongly to cell, the 0.15 welded strongly to the SS, but the copper did not weld strongly to the copper.

Also stacking and positioning 3 layers then getting the electrodes placed properly atop was annoyingly difficult..

I'm getting some 0.1mm 304 stainless steel on Monday,

0.5mm stainless is ridiculous. I am amazed it works as well as it does.
The goal will be the thickest copper welded with the least energy.