# Model Y structural battery pack



## francoisp (Sep 28, 2018)

According to Sandy Munroe, the structural battery pack has a repairability factor of zero (1:16). Not good if it turns out to be true. And it's going to make it harder to recycle and recycling is what makes the environmental costs of making the battery less of a burden long term.


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## Ed Woodrick (May 26, 2018)

A repairabilty of 0 has very little to do with recycling. First stage of EV recycling is to use the battery as utility augmentation and that can accept a number of cells being bad. 
After that you probably tend to rip the cells from each other and that doesn't really require repairabilty. 
And honestly, most car owners are just going to want a whole new battery anyway.


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## francoisp (Sep 28, 2018)

Ed Woodrick said:


> A repairabilty of 0 has very little to do with recycling. First stage of EV recycling is to use the battery as utility augmentation and that can accept a number of cells being bad.
> After that you probably tend to rip the cells from each other and that doesn't really require repairabilty.
> And honestly, most car owners are just going to want a whole new battery anyway.


You're not considering the case where a module breaks down. This is something that happens today.

And reusability and recycling are two different things. Considering how explosive lithium can be I'm pretty sure that recycling requires more than crushing the pack to extract the raw material.


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## francoisp (Sep 28, 2018)

On the


francoisp said:


> You're not considering the case where a module breaks down. This is something that happens today.
> 
> And reusability and recycling are two different things.


 On the other hand if a module does break down we won't be getting a used battery pack. 😜


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## Klaus-rf (Mar 6, 2019)

francoisp said:


> On the
> 
> On the other hand if a module does break down we won't be getting a used battery pack. 😜


I don't think we know this. An owner may "want" a new pack, but it's up to Tesla to determine what the owner will actually get. And we have already seen cases where they get a "battery pack" with no indication of new, previously owned (aka used), reman'd, whatever. As Tesla seems to just call all of them a "battery". 

Even in cases where it's customer (or insurance) paying for the replacement battery pack, Tesla does not ID if the replacement is reman'd (nor what does reman even mean?), previously-owned, new or something else. 

Pretrty much the same with ICE mfgrs - if the "engine" fails at 2,000 miles with a 36K "warranty", you will get the engine replaced and warrantied for the remainder of the 36K with no specification if new, reman, used, etc.


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## garsh (Apr 4, 2016)

francoisp said:


> You're not considering the case where a module breaks down. This is something that happens today.


Tesla doesn't repair or replace individual modules. It's too difficult to match old modules, and if they don't match, the "repair" doesn't last long.


__ https://twitter.com/i/web/status/1437607772959428608


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## francoisp (Sep 28, 2018)

garsh said:


> Tesla doesn't repair or replace individual modules. It's too difficult to match old modules, and if they don't match, the "repair" doesn't last long.
> 
> 
> __ https://twitter.com/i/web/status/1437607772959428608


When a pack is put together the first time, the modules have to be matched at least once so why is it hard to match them again? And what does matching mean anyway? Voltage? Current? I'm pretty sure not all modules degrade exactly the same way so this has got to be handled somehow by the car hardware and firmware.


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## garsh (Apr 4, 2016)

francoisp said:


> ...so this has got to be handled somehow by the car hardware and firmware.


Tesla originally would swap modules, but they soon stopped that practice, supposedly because it's too hard to match used modules, and not matching them causes premature failures. Now if there's a battery problem, Tesla will only ever swap entire batteries. I don't know what exactly makes it so difficult, or why a mismatch will again lead to premature failure.


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## francoisp (Sep 28, 2018)

Out of curiosity I did a quick search on Tesla battery repairs and I found this quote:



> In response to the claims from Hughes about these battery repairs not lasting, CEO of Gruber Motor, Pete Gruber, was confident about the work his company did in repairing Tesla batteries.
> 
> "It's simple: we figured out how to do it, he hasn't," said Gruber. "We have been putting Teslas back on the road, Roadsters, and now Model S's, for years with no issues. How does he think Tesla created [remanufactured] battery packs in Lathrop, California? We carefully match CAC (Calculated Amp-hour Capacity) values on modules to eliminate the incompatibility issue Jason talks about."


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## garsh (Apr 4, 2016)

francoisp said:


> According to Sandy Munroe, the structural battery pack has a repairability factor of zero (1:16). Not good if it turns out to be true. And it's going to make it harder to recycle and recycling is what makes the environmental costs of making the battery less of a burden long term.


Recycling is not a problem.
Watch from 7:52 for how a battery pack will be recycled.


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## francoisp (Sep 28, 2018)

garsh said:


> Recycling is not a problem.
> Watch from 7:52 for how a battery pack will be recycled.


Thanks for sharing. Recyclable but definitely not repairable. Lot's of electronics will be wasted for the sake of making this thing structural.


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## garsh (Apr 4, 2016)

francoisp said:


> Thanks for sharing. Recyclable but definitely not repairable. Lot's of electronics will be wasted for the sake of making this thing structural.


The majority of the electronics are in the "penthouse" that sits on top of the pack (below the rear seats).


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## Madmolecule (Oct 8, 2018)

As usual, the game changer is usually just hype. It is not a structural battery pack, but just a structural battery case.


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## garsh (Apr 4, 2016)

Madmolecule said:


> As usual, the game changer is usually just hype. It is not a structural battery pack, but just a structural battery case.


Wow, that video was all over the place. Took a while to find the part of the video where he says that it's only a "structural case".

Mr. Thuderf00t is wrong about that particular topic. A hollow rectangular cuboid (the "battery case") does not make for a good structural element by itself. The cells glued within it give it torsional rigidity. This applies to the batteries built using 4680 cells.

Now, I believe that the 2170-based packs that they're installing in the long-range Austin-built cars are made using a "structural case" rather than a "structural battery", but I have yet to see someone perform a teardown of that pack.


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## Madmolecule (Oct 8, 2018)

It did take him a while to get to the point, because he was really arguing massless batteries, which is even more silly. The main take away I got was that, all batteries are thin film and very fragile and are inherently non-structural. To make them small you need to keep the film as close together but without ever touching. so the battery is nonstructural, the case of the battery can be structural. But it’s really the overall box or case to protect the battery, even if it is surrounded by foam. I just don’t think the alleged structural battery pack is that different than the previous battery pack. I am not seeing the weight performance benefits And the recycling drawbacks are significant. The corporate line is that you have to grind it up and pretty much make ore out of the battery. That’s pretty much the case with everything isn’t it?

Just because Sandy had difficulty removing the foam, does not prove that it is stronger Or that foam is the best medium to add strength. I am an electrical engineer, But I haven’t seen too many foam filled I-beams, but I am sure they are out there. When I build a battery for my E bike, the welds do add strengths, And even the tape adds strength, I could fill the void‘s with foam. But regardless, The shape is custom design, to fit in a foam lined battery box, because this cannot flex or take an impact from a metal object without it getting very exciting. To save space I did use a hot glue gun instead of the normal battery holders . But I have just designed a new egg carton, using the structure of the egg, game changer


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## garsh (Apr 4, 2016)

Madmolecule said:


> The main take away I got was that, all batteries are thin film and very fragile and are inherently non-structural.


I'm not sure why you'd be so quick to believe the opinions of a Chemist who has only ever worked in Academia over the opinions of someone with 40+ years of experience in tooling and manufacturing. Or ignore the automobile manufacturer who says they're designing things this way.


Madmolecule said:


> The corporate line is that you have to grind it up and pretty much make ore out of the battery. That’s pretty much the case with everything isn’t it?


Sure. But a battery is "extremely high-grade ore" compared to what you're going to dig out of the ground. The processes for extracting the desired components are well-understood. It shouldn't be an overly-difficult process. It's not done commercially today because old/dead battery supplies aren't large enough yet to make such a recycling business worthwhile. That will change.


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## Madmolecule (Oct 8, 2018)

Sandy is very capable of taking things apart, but I do not feel he is an amazing engineer, specifically by the way he does not respect professionally educated engineers. I think he goes by feeling too much, and is still a little starstruck by Elon and recently I think there might even be some sponsorship. Oh it doesn’t take the best engineer to realize the battery is the thin film and the electrolyte, and it is not structural. There are very small gaps and you do not want to make them touch, ever. I definitely don’t believe him on face value, I just think he makes more of a compelling argument than Elon and Sandy. I don’t really trust anyone on YouTube or even opinion forums for that matter. Everyone is trying to push a narrative and control the messaging, except me, ha ha

The batteries I built for my E bikes, are from recycled 18650 battery’s. These batteries came from medical devices, like oxygen generators, that we rarely used. But there for if the power goes out. It is so much easier testing and recycling them if you can break them out of the equipment. Going to the ore stage, even if it’s quality ore it’s not good in my opinion


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## Ed Woodrick (May 26, 2018)

Maybe the way to look at this is what does the integrity of the car look like when the battery is removed. Does the battery case add integrity. If the battery case was empty, would the battery add integrity. I think that answer is yes. 

You also need to look at the integrity that is intended to be added.


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## garsh (Apr 4, 2016)

Ed Woodrick said:


> Maybe the way to look at this is what does the integrity of the car look like when the battery is removed. Does the battery case add integrity. If the battery case was empty, would the battery add integrity. I think that answer is yes.


That would be an interesting experiment. Compare chassis flex with battery, with no battery, and with an empty battery case. Though obtaining an empty battery case will be difficult.

From Munro's disassembly video, it's clear that the top sheet of the battery is much too thin to provide much structure. The side rails are quite massive to prevent side-intrusion. I'm curious to see what the bottom sheet looks like. I expect it to be thicker than the top, but if it doesn't have ribs, it's not going to contribute much to torsional rigidity.


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## Madmolecule (Oct 8, 2018)

Those would all be good test, Sadly I have not seen any of those done, which makes it very hard for me to state that it is a game changer or adds more benefits than detractions. If an internal connection fails and your structural battery pack that’s foam sealed, do you have to throw away the car? I know it is less likely that this will happen but it could be a problem. If they were to run the test and you are correct, how much weight saving do you think you could gain with the structure pack? I also don’t quite understand how it can be structural yet expand and contract with the temperature. 

The recycle aspects are still extremely troubling. I have yet to see anyone claim how this high-grade ore would be produced. I would love to see the video of someone throwing a Tesla structural battery pack into a grinder. Or maybe it can be discharged fully before this, but I would love to see it. It just seems like the most backwards recycling approach to a very valuable and expensive piece of the vehicle. All of this for very limited upside if any.


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## Madmolecule (Oct 8, 2018)

Ed Woodrick said:


> Maybe the way to look at this is what does the integrity of the car look like when the battery is removed. Does the battery case add integrity. If the battery case was empty, would the battery add integrity. I think that answer is yes.
> 
> You also need to look at the integrity that is intended to be added.


again, I am an electrical engineer so I’m out of my scope here. I’m not really sure how that would be tested. I don’t think integrity is the right word, since the battery actually adds weight and stress, so the test would really need to be a normal battery pack and a case, versus the structural battery pack in a case. I can’t imagine all that weight inside the case making it stronger, but please elaborate


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## garsh (Apr 4, 2016)

Madmolecule said:


> Those would all be good test, Sadly I have not seen any of those done, which makes it very hard for me to state that it is a game changer or adds more benefits than detractions.


It's only a "game changer" in the sense that there are fewer parts. Why have a separate "top of battery case" and "floorboard" when the top of the battery can be both?


> If an internal connection fails and your structural battery pack that’s foam sealed, do you have to throw away the car?


No. The battery (or battery case) is structural, but that structure is bolted in. It's easy to remove and replace. Just be careful not to flex the rest of the vehicle while the battery is removed.


> I also don’t quite understand how it can be structural yet expand and contract with the temperature.


Well, we'll soon find out if Tesla engineers are smart enough to have designed for this, regardless of our understanding. There's going to be a lot of these vehicles out in the wild soon.


> The recycle aspects are still extremely troubling. I have yet to see anyone claim how this high-grade ore would be produced.


Sandy explains the process here, at 7m52s:


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## iChris93 (Feb 3, 2017)

Madmolecule said:


> I also don’t quite understand how it can be structural yet expand and contract with the temperature.


Everything expands and contracts with temperature. Even bridges have expansion gaps.


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## Madmolecule (Oct 8, 2018)

iChris93 said:


> Everything expands and contracts with temperature. Even bridges have expansion gaps.


Anytime you have expansion gaps it takes away from the structure, that’s all I’m saying. And different materials expand and contract at different rates which can be problematic with pthinfilm.


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## Madmolecule (Oct 8, 2018)

Tesla made many claims about the wonders of the 4680 and the structural battery pack. It was not just fewer parts, cheaper to build, longer range and yes they touted it has a game changer not just the reduced parts. How many of these have proved to be true, how many other manufacturers are copying it?

j




Made it simple, Mass Eraser only on kickstarter


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## garsh (Apr 4, 2016)

Madmolecule said:


> how many other manufacturers are copying it?


You're expecting copies already, when Tesla has barely begun a manufacturing rampup? Other auto manufacturers have barely started making EVs at all. None of the other manufacturers are even making their own batteries. They rely on other companies for that.

Several battery-cell manufacturers have already announced that they'll be producing the tab-less 4680 cells, including LG, Panasonic, CATL, and EVE.


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## brur (Nov 15, 2018)

If the foam acts like a glue on the top case sheet then one could expect to get strength from it. Don't forget epoxy and glass-coated surfboards, model airplane wings, boat hulls, etc.

It seems there are a few industrious individuals who are put out because they can't utilize batteries from these packs.
And this does seem like a loss to them. The creative tinker is not to be scoffed at. 
As a corporate decision- the process of replacing a bad cell in an 800 cell pack is not a "have it ready for you tomorrow morning" fix. Tieing up mechanics to work on a massive electrocution hazard is a problem too.


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## Madmolecule (Oct 8, 2018)

garsh said:


> You're expecting copies already, when Tesla has barely begun a manufacturing rampup? Other auto manufacturers have barely started making EVs at all. None of the other manufacturers are even making their own batteries. They rely on other companies for that.
> 
> Several battery-cell manufacturers have already announced that they'll be producing the tab-less 4680 cells, including LG, Panasonic, CATL, and EVE.


Yes, all beta programs that I have seen. I have seen No announcements by any manufacturers that they are going to this exclusively. For that minimum 16% range increase, I would think everyone would be all over this, including Tesla. An argument could be made for the 4680 rampdown. I don’t think it is as easy creating a mass eraser as they thought it in their powerppoint, but I am waiting. they did mention the secret sauce, and that it’s hard, so I can give them a pass. I think they had to call it secret sauce because they might be sued if they called it intellectual property.


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## Madmolecule (Oct 8, 2018)

brur said:


> If the foam acts like a glue on the top case sheet then one could expect to get strength from it. Don't forget epoxy and glass-coated surfboards, model airplane wings, boat hulls, etc.
> 
> It seems there are a few industrious individuals who are put out because they can't utilize batteries from these packs.
> And this does seem like a loss to them. The creative tinker is not to be scoffed at.
> As a corporate decision- the process of replacing a bad cell in an 800 cell pack is not a "have it ready for you tomorrow morning" fix. Tieing up mechanics to work on a massive electrocution hazard is a problem too.


You agree in this case, the car would be totaled? The battery pack could be totaled and it really can’t be recycled unless converted to high-grade ore. Just don’t think that’s very responsible battery manufacturing. Unless I see how easy it is to recycle a Tesla structural battery. I would think without evidence that used battery packs from existing Teslas are probably being recycled at 100%. It is also very possible that Tessa will put some type of electronics within the structure battery pack to make it impossible for third-party people that communicate to it and a recycled application if you use the whole pack.


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