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.
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?
Possibly, or just use two layers of this thin stuff. I should highlight though that my final termination method uses a 0.9 mm busplate with holes where these tabs are soldered, so the full current will be over 200 A, but managed easily by the copper plates (simulated here using 2 mm thick lumps of copper). The tape was available from any electronics shop - this from Altronics, but I think Jaycar sells it too.
I did the exact same test but with a single piece of nickel, and the nickel glowed white hot at 30 amps. So the copper was definitely taking the bulk of the current.
@@jobmariano348 I used 0.15 mm nickel and 0.075 mm copper. This will pass 100 amps PER CELL for approximately 5 seconds. So potentially 1000 amps for your 22s pack. It will sag pretty bad at this rate, and the cells will start to get quite hot, but the conductors will manage such a high discharge rate.
@@ktestable pure nickel, but honestly I don't think it makes any difference. The purpose of the nickel is to provide enough resistance so the contact points get super hot and fuse the copper below to the cell can. The copper is carrying the current, while the nickel is just there for bonding support.
It does make a difference for the reason you explained, Resistance. The nickel coated strip will have less resistance and that will make a Better weld because of it.@@jonescg
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.
Interesting technique. Thanks for sharing!
great stuff mate :)
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?
Possibly, or just use two layers of this thin stuff. I should highlight though that my final termination method uses a 0.9 mm busplate with holes where these tabs are soldered, so the full current will be over 200 A, but managed easily by the copper plates (simulated here using 2 mm thick lumps of copper). The tape was available from any electronics shop - this from Altronics, but I think Jaycar sells it too.
@@jonescg Thanks.
What is thickness of copper strip and nicklel there?
0.15 mm nickel, 0.07 mm copper.
Is this spot weldee from ebay i saw one not sure if same
Sure is. Sunkko 709 or something.
Maybe its not getting hotter because the larger copper where you solder is the one absorbing all the current
I did the exact same test but with a single piece of nickel, and the nickel glowed white hot at 30 amps. So the copper was definitely taking the bulk of the current.
@@jonescg can you help me build what is the right thickness of copper and nickel for a 100 amps of my 22S10P batteries. Thanks
@@jobmariano348 I used 0.15 mm nickel and 0.075 mm copper. This will pass 100 amps PER CELL for approximately 5 seconds. So potentially 1000 amps for your 22s pack. It will sag pretty bad at this rate, and the cells will start to get quite hot, but the conductors will manage such a high discharge rate.
What is the thickness of the copper and the nickel?
Copper is 0.07 mm thick amd the nickel is 0.15 mm thick.
@@jonescg did you use pure nickel or nickel plated steel? thanks
@@ktestable pure nickel, but honestly I don't think it makes any difference. The purpose of the nickel is to provide enough resistance so the contact points get super hot and fuse the copper below to the cell can. The copper is carrying the current, while the nickel is just there for bonding support.
It does make a difference for the reason you explained, Resistance. The nickel coated strip will have less resistance and that will make a Better weld because of it.@@jonescg
@@starcitizenmodding4436nickel coated steel actually has more resistance which is why it generates more heat