Modules are made .5mm larger in diameter. That should acomodate these cells vut scaling to 101% should be fine to be safe. I would print sample and see how better they fit
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Took a look at the ipt model, Yeah I’ll try scaling 1% in x and y axis.
Are the stl files on The 3D models of 18650 ・ Cults up to date with the ipt models?
Yes, cults3d has most recent files. Dont forget to scale the lid too.
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Series busbars are coming and will be available shortly, 1 to 2 weeks
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Finished up 12V UPS replacement battery with lifepo4 cells. This is just to show how you can use pcb’s to integrate BMS systems so its just a bolt job.
This particular one had 20A continues output.
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21700 MODULE V2 VENTED
Scaled 101% in both diametral axes for P42A cells
2S2P test print in PETG per the instructions in cults (except only a 0.2 first layer. 0.25 first layer caused issues)
Excellent fit. You can see how close the lid fits by looking at the “v” feature through the vent. There’s basically no gap.
I have no other reference, but when physically shaking them, they only move along their long axis (bc there’s no NESE tabs installed yet)
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@Agniusm , as said above, I scaled the model at 101% in the diametral axes. Is this level of fit & gap acceptable?
It appears that the 21700 P42A cell length + the foam is slightly bulging the module sideways. It was difficult to get this lid on. What would you suggest?
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FYI, I could not make good use of the triangular channels for zip ties. No matter how tight I pull (including with pliers), the full stack up is not rigid. I tried multiple size cable ties, multiple locations. It still allows easy movement. I’ll probably go with strapping tape instead for a low profile fix.
The other option would be one large custom 3D printed ‘washer’ under all fasteners. One plate on top, one on bottom, but I worry about having enough thread engagement and tape is quick.
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I was wandering if anyone has inspected the cells after using battery for some time? We have here one pack with black marks and i would like to figure out what’s causing it. Some suggested that its from arcing caused by bouncing cells but i cant still believe that they are bouncing, especially in flat orientation, bottom deck mount. Here is the thread: https://forum.esk8.news/t/northern-light-flight-safe-switchblade-with-reverse-mounted-urethane-gear-drives/56826/116?u=agniusm
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Hi, I’m planing to rebuild a battery pack that I had made with spot welding/soldering.
Does anyone have any experience using reclaimed cells? Is there an issue if the + and - terminals aren’t completely flat. Should I grind the nickel residue?
Yes you should try to grind any remaining nickel off. I sort of used reclaimed cells in mine and the little spikes of nickel I couldn’t tear off; I got with my Dremel sander wheel for a couple seconds.
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Thanks. Did you use them in N.E.S.E modules too?
I did.
Ok. So there should be no issues? Cool. What did u use for the series connections? The original buss bars or crimped silicone wire?
I used the bus bars as well as some short 10awg wire with ring terminals on both ends
Here is one of my three sections drawn in MS paint
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I took cells out of some broken packs and used them in my NESE pack. I grinded the nickel with dremel, I used hard pink tool to remove nickel and then I used this sesame rubber tool to smooth it out even more. Then I cleaned it with alcohol.
If the terminals are deformed, I would discard those cells and maybe only use them in flashlight or something like that.
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Cool, thx, I feel much better doing it after hearing that it has been done before.
Do you have any pictures of the cells by any chance?
