Spot Welding Copper Strips to 18650 Battery Cells

[garolittle]

Actually the PA250i can spot weld .40mm thick cooper.

https://youtu.be/mqJaKNb8L5M

 

[ak136]

I am really sad that this topic has died down...
Its been a fun journey for me reading through all of it.
Thank you all

 

[ichiban]

Actually, this is not end yet. There is another thread : https://www.endless-sphere.com/forums/viewtopic.php?f=14&t=108006#p1579840 with similar interests. Check it out.

 

[john61ct]

Actually, this is not end yet.

And thanks for your contribution here

https://endless-sphere.com/forums/viewtopic.php?p=1739908#p1739908

 

[churandy]

1200 amps from the 38P

You only need thick copper buses at the two pack ends, the positive and negative collectors. You are only drawing 31A per cell, so 0.20mm thick copper is all you need for the cell buses. Making those buses thicker will not help, and it would make welding more difficult.

If you were mapping the current, the copper bar shown could be thinner at the two ends, and thicker in the middle next to the connecting bolt.

With wat mechanism did you make these indents? You seem to have made them very systematically, and I also need to manufacture a bunch of these sheets. Do you have any tips?

Kind regards

 

[spinningmagnets]

Those pictures were produced by a different builder, and he made a press and die set. I don't remember the original link, but the press and die are similar to the one in this thread:

https://endless-sphere.com/forums/viewtopic.php?f=14&t=57810

 

[NyyphoHerr]

Hi to All.

0.3 copper strip to steel:

Supercapacitors "3000F 2.7V", 6S:
25 ms, 15 V (>10V under impulse), >2000A >= 500J (Ws)

0.2 copper strip to 18650:

Noninvasiveness test of spot-welding on a sheet of coated paper

 

[NyyphoHerr]

.....

1> Flip it - from what I understand (my welder is due for delivery today) while welding copper to nickel is a challenge, welding nickel to copper is trivial.

So if you're using cell holders, and your arrangement is symmetrical or mostly symmetrical, you could lay out your nickel parallel strips using the empty holders as a template, then lay your copper series strips with a slot or notch cut out, and weld the copper to the nickel.

Once the sheet is welded up, assemble the cells in the holders, flip the sheet and lay it on top and weld through the holes/notches, welding the nickel to the cell tops.

I see no reason this would not work, but it obviously is cumbersome, and potentially increases risk of a mishap when laying down the sheet across a large pack.
......

Cu 0.2+Ni 0.2 to steel 0.5: