I might be stupid or something, but i still cant figure out what width and thickens of nickel strip I need. I’m building a 10s3p pack from 30 Molicel P26A (2600mAh, 25 A cont.) For connecting the 3 cells into a 3p pack I have 7mm width and 0.3 mm thick nickel strip. Am I right that I need series connections capable of 75 A? How nanny layers do I need. There is conflicting information about how much current a particular nickel strip can carry.
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Unless you have a QUALITY spot welder, .15 is about the limit. Double up for thicker and more amps.
Also, use ganged strips. They will carry more current.
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This might help.
The local e-bike shop that builds batteries for themselves will do it for me for a small charge. Im pretty sure they have a decent welder. Sorry don’t know what a ganged strip is. Google search didn’t help wit that ether. The guy in the shop said they don’t double up on nickel strips because its not a good way. Don’t really know why because everywhere where I looked people are doubling strips. He also said they can weld much more than 0,3mm thickness. @kavic5150 Thanks I have watched that video. If I follow his advice I would need 5 strips per S connection with 7x0.3mm Nickel.
75A / 15 A (acceptable current) = 5 Strips. That seem a lot. Or do I have to take 50 A max because that is what my VESC can handle continues? What about peak current draw, can I neglect that? I want it to be as safe as possible.
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Pretty sure ganged strip just means doubled or tripled up.
Sounds like the bike shop is your best bet. It does take a better than average spot welder to do 0.3mm thick nickel strips. Something like a Kweld or a Sunkko.
If I’m not mistaken, most if not all of the current flows directly thru the weld spots when it goes in and out of battery cells. Thats why you see builders loading up nickel strips with as many spot welds as they can. Doubling or tripling nickel strips just adds more room for mistakes.