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Discussion Starter · #1 ·
So for years I've been hearing that tearing down Tesla packs was "impossible" because they have like, 5 layers of plastic and metal bonded together and the last layer in particular is glued down to the cells.

Tesla packs don't get used as often as they otherwise might be in DIY EV conversions because the form factor is just too large. To get 400v out of it, you basically have to use the entire pack, and donor cars just never have as much room to fit all those batteries as the Tesla designed for them did.

Well, two (Dutch?) guys with a couple beer in their garage who wanted them for e-bike packs just stuck with it until they figured out what works. They tried just about everything (pliers ripping chunks of plastic off, chisels, hammering a meat cleaver along the outside lip, etc), and eventually what became the obvious choice was to use an oscillating tool to slice the plastic.

Seems like it's fastest to take it apart 2 rows at a time, the plastic will still break apart after that.

Honestly, doesn't seem like it's all that much time if you were to start with the solution they figured out at the end of it. Maybe an hour per module? Maybe 2? For a car-sized project it seems reasonable.

The end result of course being that Tesla packs go from having the most ungainly form factor, to the best form factor that could be made to fit anyone's car, albeit with extra work building your pack.

Video is kind of a waste of time. Watch the early part, watch the end, skip the middle where they're trying all the dumb things that didn't work. It's just fly-on-the-wall footage, there's no narration.

 

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Any chemists in the building ? Lol

So the most difficult part from what saw is the last layer of glue/plastic that bonds each battery cells as a single module. Perhaps if there is a chemical that dissolves the glue/plastic but doesn’t hurt the metal casing of each cell? One can dip the entire one side in the chemical solution to dissolve it and release the battery cells . Then repeats on the other side . Only issue is it might be conductive and short circuit .
 

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Any chemists in the building ? Lol

So the most difficult part from what saw is the last layer of glue/plastic that bonds each battery cells as a single module. Perhaps if there is a chemical that dissolves the glue/plastic but doesn’t hurt the metal casing of each cell? One can dip the entire one side in the chemical solution to dissolve it and release the battery cells . Then repeats on the other side . Only issue is it might be conductive and short circuit .
I haven't seen it up close myself, but it may be some epoxy like resin that's used. There are no good solvents for epoxy, so it's a non-starter.
 

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It's not impossible for the S/X modules - who told you that?

It takes about 3 hours per module, and the fun, in an otherwise boring menial effort, starts when you accidentally pierce a cell while chiseling it's bretheren out.

Roman candle that goes off, which then starts the clock on getting it out before it lights off its neighbor(s). The three year old watching me work the cells out from a safe distance was amused.

You want to do this outside...
 

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I haven't seen it up close myself, but it may be some epoxy like resin that's used. There are no good solvents for epoxy, so it's a non-starter.
Wrong.

It's a plastic that dissolves in acetone - my buddy extracted his that way. Then I pointed out to him there's a plastic spacer below the vent inside the cell...

Mine were pulled using a flat blade screwdriver and hammer. The plastic cracks, at which point you can pull the cell out.
 

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It's not impossible for the S/X modules - who told you that?

It takes about 3 hours per module, and the fun, in an otherwise boring menial effort, starts when you accidentally pierce a cell while chiseling it's bretheren out.

Roman candle that goes off, which then starts the clock on getting it out before it lights off its neighbor(s). The three year old watching me work the cells out from a safe distance was amused.

You want to do this outside...
I need to open up these (80Ah) for an investigation (they're completely dead at the terminals, but I bet they're still charged, just some kind of mechanical failure in the electrodes), any advice on how to do it safely ?

123511
 

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Wrong.

It's a plastic that dissolves in acetone - my buddy extracted his that way. Then I pointed out to him there's a plastic spacer below the vent inside the cell...

Mine were pulled using a flat blade screwdriver and hammer. The plastic cracks, at which point you can pull the cell out.
Oh so there is a plastic spacer in the battery cell itself ?..Bummer . I guess best way (for least effort) would then be those oscillating tools from what I’ve seen.
 

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I need to open up these (80Ah) for an investigation (they're completely dead at the terminals, but I bet they're still charged, just some kind of mechanical failure in the electrodes), any advice on how to do it safely ?

View attachment 123511
You're getting into cells. I was extracting cells.

I doubt there's a "safe" way to get into a charged cell. Especially if it fused, which it sounds like happened to the electrode connection.

Industrial xray/CT is the best method. Get in it without getting in it.
 

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Discussion Starter · #11 ·
It's not impossible for the S/X modules - who told you that?
People here have been saying that for years, that there's no point, that it can't be done, that they're glued in and you'd never get them out.

This was the first time I'd seen anyone share their successful attempts.

When you successfully extracted cells, did you share your success and methods here?

It's a plastic that dissolves in acetone - my buddy extracted his that way. Then I pointed out to him there's a plastic spacer below the vent inside the cell...
That was my concern.

However, the bottom of the cells are continuous and should be just fine to be dipped. At which point, prying them out of the top should be pretty easy, they'd be dangling loose like grapes.
 

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I wouldn't call lighting off a cell successful nor would I show a method that is a massive, nonextinguishable fire hazard and carries a high risk of 3rd degree burns to people in the 75th percentile of being mechanically inclined. The video shown here is intensive, but seems to work...if you don't create a short and if you don't breach a cell.

The dip, bottom down, is a good idea if you have a large enough nonconductive tank and a fat wallet for the acetone needed and for its proper disposal. The challenge will be keeping over 400 cells from keeling over once the plastic is dissolved
 

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Discussion Starter · #13 ·
I wouldn't call lighting off a cell successful
Okay, well, you can't make the argument both ways.

It's either well known and easily possible to disassemble Tesla modules for their cells, or, it's difficult and unviable.

I've only seen the difficult and unviable declarations for the last... 10(?) years these modules have been available to the DIY community. This video showed it's a bit crude, but nothing fancy is needed nor is it especially dangerous. They went through a variety of methods until they found something that worked for them.

Sharing attempts, partial successes and failures is of value in the DIY community too. Maybe it saves someone some time, or maybe it gives someone an idea of what else to try. Building on each other's knowledge; kind of the point of a DIY community. Unless you're just out to sell EV services and to scare everyone into thinking DIY is impossible and must be professionally done.
 
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