I had one of these and it died the second I plugged it in. Lol. Get something better.
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Soo
After some time I got my hands on a better spotwelder. This one’s chunky.
The guy who I got it from managed to weld .20mm nickel perfectly
I couldnt replicate the same result with 0.15mm nickel, here are some pics
Simply the nickel wont stick to the cell
Both are clean
Could it be that the electrodes are too far apart?
This is actually beneficial and not a detriment. What kind of welder is it? Did u ask ur friend what his settings were that allowed him to weld 0.2mm nickel? That’s where I’d start. Hard to help you without more info about ur welder.
I hope this doesn’t ring any bells but it’s a diy spotwelder, I don’t know how many amps, he said I should keep the amps nob on 99 and play with the time (1=20ms) and it worked for him at around 7-9
I was able to replicate some good welds with my stuff
Now my new question is, when spotwelding what counts as a good spotweld? If I tear off the nickel strip should it leave a small amount of nickel on the cell where the spotweld was, puncturing the strip or should it just come right off with some medium force applied and no residue, only some greyish spots
I thought electrodes close was better than far apart, no?
Where u live? Maybe someone could weld it for u if close. I’m in Bay Area Cali.
the nickel should rip n leave some behind if it’s a good weld
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Like @hummieee said. If you tear off the nickel from the cell it should leave holes in the nickel strip with nickel left behind on the cell itself.
I use a Malectrics spot welder and with a 15ms - 20ms pulse .2mm is easily bound to the cell. Keep dead cells handy to test and/or practice your spot welding
No, you want the electrodes relatively close together, to far apart is generating excess heat and losing power in the weld.
I can’t be 100" sure because you’re DIY spot welder leaves a lot of factors in the air, but generally total lack of pentation is because you’re applying to much pressure to the electrodes. The airgap is what creates the resistance needed to make a spot weld, if you’re pressing the nickel to the cell to hard and that “gap” is negligible, resistance goes down spot weld doesn’t occur.
Bottom right is to hot, top left is to week, you should be looking for something in between the top right and bottom left. Very small heat ring around the weld is acceptable, but large discolorations are not good. Either way, needs a pull test to be sure the welds are sticking.
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In real life these don’t look as bad I think.
I’ve sharpened the electrodes and it made a huge improvement, but after like 10-15 welds they got dull again, could it be from the excess heat? This is what a pull test showed after I sharpened them:
Also how can I safely remove the nickel residue?
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Tellurium copper is what you want for electrodes. They hold up way better than the cheap soft copper ones.
You can grind off the nickel carefully with a stone wheel on a Dremel type tool.
You got a source on this? Everything I’ve read indicates ~3 cm as ideal but I’ve never read anything suggesting more than that causes the issues you’re mentioning. Also, when we’re welding terminals on batteries getting much further apart than that is pretty much impossible anyway.
3cm is “too” far, possibly impossible. 3 millimeters. Makes sense to me to be as close together as possible.
Exactly my point. We’re already much closer together than 3cm esp on the pos terminal so it would then follow that we would want as much space between the probes as is possible in this application.
For reference:
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That site doesn’t seem real. There are some very serious dimension inconsistencies/errors and strange use of language.
Fair enough but it’s in line with other stuff I’ve read. Think another rule of thumb I’ve seen thrown around is a minimum of 10x the thickness of the material being welded. In any case, what I’m interested in is a source saying that closer is better bc that’s the opposite of what I’ve seen just about everywhere.
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I’ve bought better material electrodes, works like a charm now
I have another question though:
When stacking nickel strips, should I stack them in way all the cut out lines in the middle match up or should I rotate the layers so they overlap?
Also I’m planning on double 10awg series connections, but how should I connect that to the xt90? A bit too much cable for a relatively small connector
Again, I want to make it as safe as possible considering I’ll possibly be driving this pack on a lot of amps
dual 10awg is way overkill for a 12s4p.
Dual 12awg is still a bit overkill, but say that, and single 10awg going to an xt90 should be more than sufficient.
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Your pack will be fine w 2 x 14 awg for series connections and 12awg for your main terminals. Anything more than that is overkill. If you had more cells in parallel and/or were building a mountainboard than 2 x 12 awg for series and 10 awg for your main terminals would be sufficient.
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What about the first question regarding the positioning of the nickel strips?