Kind of an update but not really - it’s relevant. Here’s a timelapse of my friend and I disassembling his set of 10 packs.
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how many good batteries came in those packages?
All of the batteries themselves were good, we lost 12 while disassembling though. It’s just so easy to rip a hole in the positive end. Quite unfortunate but it is what it is.
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Is it a bad idea to just spot weld over the thin nickel?
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I’m sure you guys figured this out by now, and apologies if I’m repeating (just sort of skim read the OP), but at least with the A model cells (I’ve got lots of those on hand) the positive side is connected to the case of these cells and the wrappers are pretty fragile. It’s easy when prying nickel on the negative side to short against the corner of the case if you lever against it, and these things can dump crazy amps, so keep that in mind when the sparks fly!
I’ve reclaimed these from packs in 12 and 16p groups with continuous nickel, gotta be carefull to peel the nickel back rolling up on itself on the neg side first then stripping the positive side is easy.
I haven’t run into too much of the end perforation probs, EMC must have welded the shit out of these? Did you guys consider just cutting the tabs an leaving the nickel on? Would give you something easy to weld/solder too anyway since you can get at them pretty easy it looks like with side-arm cutters?
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Shouldn’t be really, you can always grind them down a little more flush, it should just increase current carrying capacity. As long as you’re not relying on specific geometry as a fuse.
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Not sure, I didn’t want to for cleanliness sake.
With the method I suggested, you don’t pry against the case. I didn’t have any issues with breaking the wrapping on the cells.
I’m not sure really what you’re referring to here but all of the cells in these particular packs are spot welded in single units to the boards. And yes some of them were welded way harder than others. I think the welders they use aren’t super consistent in weld strength
Like I said, I personally didn’t want to because of cleanliness. It makes the pack thicker and more annoying to weld to an inconsistent surface. Grinding all of the cells would have taken longer than taking the bits off - trust me I know, I ground 80 18650’s before in a siting and went through 1.5 dremel tips doing it
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Yeah man, I was describing the packs I disassembled in terms of rolling the nickel back on itself prying away, they were in large tightly packed P groups, no boards. Just adding to the A123 info here is all. Not critiquing your methods bro!
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Ah gotcha. Yeah that sounds annoying lol no offense taken or anything
I would say taking the nickel off was definitely the most annoying part, but in the pack we planned to use them in, we didn’t want little bits of nickel hanging off the ends and such
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Hah yeah, I guess with a dremel that makes sense, I have large abrasive belt grinders, it’s literally about 50ms each to dust them off…
If you ever have to do it again though, consider using a large flat plate, countertop, surface plate, piece of granite/marble tile and glue a piece of 80ish grit paper down, press the part you want to flatten straight down and drag it across, this is technically “lapping” and it’ll go a lot faster than dremel, plus get flatter.
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I’m envisioning you also have some kind of swing arm with a vertical V block for keeping cells straight up and down.
Hell throw a motor on there and it’s automated!
3D printer attachment? 
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Haha you could, but TBH you develop a technique pretty quickly involving 3 fingers on each hand and you “feel” the flat. You’re not lapping for high precision here, important thing is to only put downward force in one stroke direction. i.e. only attempt to remove material in the pull, or the push. It’s pretty easy.
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Oh boy haha that’s a different animal
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I finally followed your guide!
I found it really hard to break the tab off the pcb without shorting the tool on the outside of the cell. had it happen with like 3/8 of the first pack I just did. The solution is to reall tear up the PCB carefully just enough to be able to rip the tab the not too much where the side cutters touch the cell.
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Great to hear it helped someone! Yeah it was always easiest when you break it right against the tab so the tab basically falls off of it. Exactly what tool you use makes a difference too, one of the pliers I had worked way worse than another pair
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