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Recently switched to a 100Ah 800CCA car battery and I can now weld an entire pack (or more!) in a day; no more recharging small lipos 
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As Hobbyking is often out of stock on my recommended Lipos, I’ve bought and tested a few more models. I can recommend these two:
https://hobbyking.com/de_de/turnigy-nano-tech-plus-5000mah-3s-70c-lipo-pack-w-xt90.html (calibrates at 1570 amps when fully charged)
https://hobbyking.com/de_de/graphene-5000mah-3s-75c.html (calibrates at 1520 amps when fully charged)
Unfortunately, as of writing this, also these have gotten out of stock… My order was just a month ago.
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me 
We’re progressing, although slowly as my main engineering service tasks are eating up most of my time, and I’m shooting for the first 20 or 30 prototypes to offer to you guys.
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Send one to @glyphiks if he says it don’t overheat and can do thicker than 0.2mm nickel well consistently I buy one.
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I would more-than-likely be in for one as well. Been waiting somewhat patiently for project updates 
Haha i feel like that would be a walk in the park for this beast
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Does anyone have experience with different copper nickel sandwiches?
I have nickel plated steel (0.15mm) and am wondering how thick the copper can be (0.1mm vs 0.2mm).
Would be grateful for any experiences and settings.
doubt that was pure copper (unless you used a sandwich method or have very high current capability)
with 1400A and pure copper i can’t even get it to stick at 60J, unless i use .15 nickel plated steel ontop of it, then the strips rip off the cell (good weld), leaving pieces of copper behind and holes in the strip.
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.15 nickel plated steel with 0.1mm copper sticks perfectly with 60J in my case
doubt you need more, 0.1mm copper has the same conductivity as .4mm pure nickel strip and 1.6mm or more nickel plated steel, some say pure nickel is 4x more conductive, some 10, so could be like 4mm nickel plated steel, idfk, but it’s insanely conductive either way
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Getting into spot welding myself and decided on the Kweld
Would something like this work with the K-weld?
Does anyone recommend it?
https://www.aliexpress.com/item/1005001603504218.html
And what is the 2023 recommended lipo? Last I read it was this hobbyking graphene lipo: https://hobbyking.com/en_us/turnigy-graphene-6000mah-3s-75c-lipo-pack-w-xt90.html?___store=en_us
Thanks
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- Turnigy nano-tech 3S/5000mAh/130C Lithium Polymer battery (link or link). I have stress tested one of them for several complete discharge cycles, and it shows no visible swell thereafter. The measured current is 1300-1500 amperes.
- Ultracell UXL65-12 (link). According to feedback from a user, the current reported by kWeld is approx 1000A when tested with 0.15mm nickel strips.
I use 2x of the ones you linked in parallel you want as many Amps as possible but don’t exceed t2,000A
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How many welds can you do with 2 in parallel?
I wanna weld 70-100 cells before having to recharge. (a complete pack in one go)
That will be a piece of cake for this machine. I am about to stress test it with 200J pulses once per second (at output terminals, that translates to 100…150J at weld spot depending on output leads). It is designed to sustain that. The setup will include water cooling the test load in a bucket with water exchange via tap water.
Regarding the progress: I wasnt able to progress as fast as I wanted, because we had to do firefighting for weird firmware bugs in a customer project, literally for several months in a row. Conclusion: Wireshark does not see everything bad happening on USB, but thanks to the makers of the Beagle USB sniffer we managed to find a solution (also, thanks to Microsoft for making USB things different since Win11… 
).
At the moment, I am close to ordering a first batch of maybe 30 preproduction boards. Firmware development will take quite a bit more time, and therefore it is my idea to do the most important stuff first and then publish a number of firmware updates. For example, remote control via USB will come later, among other not so mission critical features. The GUI development is going nicely, attached a short clip of what this looks like at the moment. Last week I have started the enclosure design, which will be done by a fellow mechanical engineer who is mindblowing in SolidWorks. The enclosure will be punched, embossed, bent steel with powder coating, so there will be a sampling batch followed by a larger one. These processes require tool manufacturing, so that might become the bottleneck towards my goal of having the first smaller batch of units ready before this Xmas
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I got my K-weld and just got it all set up
Any Joules recommendations for 0.2mm nickel plated steel?
I started with 25J and it looked fine. And ripped up leaving dots.
I tried 18J and it looked almost the same. And ripped up leaving dots too.
Should I keep lowering until it stops leaving dots when I rip the nickel? And then increase that minimum by 5J?
Thanks
And what grit of sandpaper do you guys recommend to clean the probes?
Thanks
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Are you sure you have .20 nickel lol
Are you welding these into real cells and testing?
I weld my .15 at 37.5J and your thickness at a higher amount
He said nickel plated steel, makes sense he needs less energy