Spot welding a nickel sandwich

This technique will help with nickel tab connections required to pass serious currents. And it's surprisingly simple!

[markb]

This is a good technique for using spot welders without industrial levels of power output to still be able to weld copper strip to cells. It works quite well, too.

Because copper has such a low resistance, attempting to spot weld only copper strip to cells is quite difficult, because the resistance at the electrode tips is too low to generate the heat needed to make the weld. Using nickel strip, which has substantially more resistance, becomes far hotter at the electrode tips and it is this heat that welds both the nickel and copper strip to the cell. Very effective method for high current bus on battery packs.

[mattrenegar]

Interesting technique. Thanks for sharing!

[diyzona]

What is thickness of copper strip and nicklel there?

[MiniLuv-]

Like that!
I wonder if multiple sheets of copper spot welded together could be used as flexible bus bars for several hundred amps? Where did you get the copper tape?

[jobmariano]

Maybe its not getting hotter because the larger copper where you solder is the one absorbing all the current

[freddywrx]

Is this spot weldee from ebay i saw one not sure if same

[Omar-tzhx]

What is the thickness of the copper and the nickel?