2022 Model Y 4680 Structural Pack is "Amazing", Says Munro & Associates

Munro & Associates has just released an analysis of the structural pack for Tesla's 4680 battery cells, having just received a 2022 Model Y SR from Giga Texas.

In their analysis, Cory Steuben (President of Munro & Associates) and Julian Aytes (lead engineer) found that the car's front seats are directly mounted onto the structural pack itself, making the structural pack essentially the vehicle's floor itself.

"It's absolutely mind-blowing to be standing under a vehicle on a hoist and have absolutely nothing for the floor structure. To truly understand how amazing it is to see a vehicle with no floor and the seats mounted to the top of the structure on the pack, you have to go back more than years, but decades."

(Source: Munro & Associates)

The structural pack, including the seats and other components mounted to it, weighs 1,198 pounds, which is "incredible because in a couple of the other EVs we have, the batteries will weigh twice that. Just the batteries. No seat, no carpet, no trim."

According to Elon Musk, the structural pack is "the right overall architecture from a physics standpoint, but still far from optimized," which seems to be a modest take on the speed of Tesla's design improvements.

https://twitter.com/x/status/1544511999392071680

Despite minor manufacturing issues found by the team, the Giga Press casting machines, noted as the world's largest high-pressure die casting machines, have done an amazing job at astronomically decreasing both parts and complexity for the structure of the chassis itself.

"At Munro & Associates, we've seen the development of the automotive industry for the past 30 to 40 years. I've come from a background of benchmarking vehicles where you'd have hundreds of stamped parts where this front giga casting is, and hundreds of parts in the back. The level of refinement and integration is incredible. Tesla is not waiting to integrate the casting for multiple mounting features."

Overall, these improvements have come from decades of constant work and continuous improvement on Tesla's end, and it is clear to see why Tesla is so ahead of many other manufacturers in terms of vehicle and battery structure.

Steuben mentions that the next goal for their analysis is to remove the battery cover and be able to know how Tesla is securing the 4680 cells themselves and take a look inside the battery pack itself.

The full breakdown and analysis is linked below.

 

[ZenRockGarden]

https://www.tiktok.com/video/7118065302872591659

 

[AlanSubie4Life]

https://www.tiktok.com/video/7118065302872591659

Yeah will be interesting to see how much if any of the pack is empty cells. If they've actually realized most of the gains without chemistry changes, seems like they should be able to fit 100kWh in this Model Y pack. (1.3 * 78kWh (2170), not 1.3* 82kWh (2170L)). I assume cell design and vehicle integration would be realized now in this first 4680 pack.

But the weight of the vehicles suggests no density improvement, unless the empty spots are filled with relatively heavy fillers for structural reasons (would be a bit of a drawback of a structural pack!).

Of course, the current 68kWh degradation threshold pack could have substantial capacity hidden (not locked out), but that should become evident relatively readily to anyone scanning the pack with SMT; it'll just show the capacity (unless there is a lockout). Seems unlikely they've hidden more than 5% extra in any case (that's about what they did with the first Model 3 LR RWD; when they increased the range from 310 to 325 it was all from a release of hidden capacity from what I can tell (degradation threshold increased from 310mi*234Wh/mi =72.5kWh to 325*234Wh/mi = 76kWh, and the pack itself always had 78kWh of capacity per EPA test result from 2017).

Over the next few years or so, once they fully implement all of the 4680 improvements (Cell design - 16%, Anode Material-20%, Cathode Material-4%, Vehicle integration-14%), the range increase will be 54% total. Nothing about what the range of any of the vehicles utilizing the new cells will be. The range of the cars will just depend on how many 4680 cells are used in the battery pack.

 

[ZenRockGarden]

Yeah will be interesting to see how much if any of the pack is empty cells. If they've actually realized most of the gains without chemistry changes, seems like they should be able to fit 100kWh in this Model Y pack. (1.3 * 78kWh (2170), not 1.3* 82kWh (2170L)). I assume cell design and vehicle integration would be realized now in this first 4680 pack.

Keep in mind that the larger 4680 cells are inherently less space efficient than their smaller-diameter 2170 cylinder siblings. The gains in cell efficiency have to make up for that before they produce overall increase in pack density.

 

[AlanSubie4Life]

Keep in mind that the larger 4680 cells are inherently less space efficient than their smaller-diameter 2170 cylinder siblings. The gains in cell efficiency have to make up for that before they produce overall increase in pack density.

Can you link to this space efficiency analysis? With the exception of the pack edge effects and cell edge effects, purely looking at the packing of cells geometrically, the size of the cell will not impact space efficiency at all; it's just a scaling with the same whitespace % if I'm thinking about it correctly (obviously these edge effects and cooling requirements would matter in reality, which is why I ask for the link since I haven't looked into the analysis or thought about it in detail). But you'd think the containers of the smaller cells would lead to more overhead so I guess I'm confused by your claim overall. Also the 4680 are 14% taller so if somehow they can get that extra 10mm for "free" (due to structural packing (airplane wing tank analogy or whatnot) or whatever magic they have claimed which may well be dubious - but it looks like they've integrated the lid of the pack with the floor of the car which would definitely save some space as required), that would also help.

It just seems like larger cells would be more efficient if there is significant packing overhead at the cell level (I don't know exactly how much packing overhead there is on a 2170 cell - obviously this would be minimized and they are pretty thin walled).

And the idea of the tabless design I thought was also to improve thermal conductivity (vague recollections) top and bottom of the cell, though obviously cooling snakes are still needed, maybe there is some room to be saved there too? Seems tricky since a larger cell would be difficult to cool if you're not cooling it from the conductive top/bottom.

So, per unit volume (of the individual cells), what's the energy in a 4680 cell vs. a 2170 cell? (Wh/cm^3) That's obviously one fundamental measure. That's what I would call "cell design" improvement (which they claim to be 16%). The 14% conveniently aligns with the integration of the top lid with the vehicle (80mm vs. 70mm with no change in cabin volume or vehicle size), so I'll assume that's the vehicle integration component they refer to.

It sounds like you're saying a 4680 is less energy dense than a 2170, which doesn't seem reasonable at all and would not be what I would expect.

 

[P3dStealth]

After watching that video with the pink foam 20 times.... My non-expert analysis is that I have no idea what is going on lol.

Best guess they covered the batteries with a sheet of something nonconductive and then covered that with the foam. Maybe it's to protect the occupants since the floor is now the battery pack. The floor seems very thin which is fine because they filled any gaps with foam. It's probably serving multiple purposes, vibration protection, fire retardant, insulating the cabin floor from battery heat, adding color to the inside of the pack....

I want them to post a video of someone just grabbing a chunk and ripping it off.

I am not an engineer but I watch all of the tear down videos. It's just interesting.

 

[AlanSubie4Life]

It sounds like you're saying a 4680 is less energy dense than a 2170, which doesn't seem reasonable at all and would not be what I would expect.

Roughly speaking I'd expect each 4680 cell to be 100Wh or so. As compared to the 18Wh or so of the 2170 (not the 2170L). The estimates of 800 or so batteries make that a 80kWh pack which doesn't align with the 68kWh visible in the GUI so far (but there's way's to align those numbers).

Anyway 100Wh would be the same energy density roughly as the 2170. 28000mAh. (I see some bizarre references on the internet to much lower numbers than this which make no sense.)

I guess we'll see.

 

[Jayohee]

54% improvement in range. Thats really impressive that the Austin Y's now have that much more range as Tesla promised.

"According to Tesla's Battery Day presentation, all the cell chemistry, design, and manufacturing advancements that come with the 4680 cells amount to a 54% improvement in range, 56% improvement in cost per kilowatt-hour, and a 69% reduction in capital expenditure."

I think this means Tesla can make more cars with less batteries. they will not be increasing the overall range for the MY as much as fulfilling the demand. Still a step in the right direction

 

[ZenRockGarden]

It just seems like larger cells would be more efficient if there is significant packing overhead at the cell level (I don't know exactly how much packing overhead there is on a 2170 cell - obviously this would be minimized and they are pretty thin walled).

I do hear you that ideal-cylinders in conveniently ideal containers have a consistent space efficiency a bit over 0.9

However bigger cylinders run into a lot more boundary problems as you try to fit them in a pack of rather pre-determined size, and the cutaways for 4680 were showing required snake-ribbon cooling along the sides of the larger (and thus harder to cool) 4680 cells.

Basically everything is easier when your cell size is smaller, there's more surface area to cool on per volume cell, and you're not having to punt and put large blocks of foam (or weird pink goo?) to fill in the places where another large-diameter row of cells didn't fit....

 

[evphile]

Did everyone see/hear on that video that they are offering the 800 or so 4680 batteries to 1C1S buyers @ $800/ea…??? Would love to see someone’s YouTube video on what things can be powered by one 4680 cell and—finally—would love to see them cut it open and take a peek inside!

 

[AlanSubie4Life]

and the cutaways for 4680 were showing required snake-ribbon cooling along the sides of the larger (and thus harder to cool) 4680 cells.

How do you think they cooled the 2170 cells?

Basically everything is easier when your cell size is smaller, there's more surface area to cool on per volume cell,

True. One advantage of the “tabless” (“all tabs?”) design was the ability to cool from top and bottom as well as the sides. Which may still happen to an extent. It’ll be interesting to see whether the internal cell construction lives up to the promises. I would think the cooling via the terminals would be essential in such a large cell.

However bigger cylinders run into a lot more boundary problems as you try to fit them in a pack of rather pre-determined size

Yes, there is more overhead on the edges as I mentioned.

 

[ZenRockGarden]

How do you think they cooled the 2170 cells?

they ran very thin cooling strips between every other row of cells, not huge ones for every single cell

 

[Krash]

Suppose Tesla or a third party eventually made a 4680 retrofit for the classic model S/X. How much would the pack stick out (down)? i.e. how much height would the tabless design save? Any other height savings?

80mm - 65mm - tabless savings - ?

 

[Krash]

Also, if there weren’t thermal reasons why you couldn’t fill the gap between 4680 cells, how much electrical capacity would could an ultracapacitor have in that volume at current energy densities? At projected densities in ten years? Is is easier to make ultracapacitors in goofy shapes than batteries?

 

[AlanSubie4Life]

they ran very thin cooling strips between every other row of cells, not huge ones for every single cell

So pitch = 46mm + X + Y where X is cooling snake thickness and Y is other overhead.

Whereas for 2170 (if it is as you say) it is every:

Pitch = 42mm + A + B where A is cooling snake thickness and B is other overhead.

So it’s possible it’s nearly exactly the same pitch (someone should measure!), but with cooling on every side of every (larger) cell for 4680.

I’m interested if they’re actually able to get any (conductive?) cooling top and bottom as they promised (I think) with the tabless design. Seems they may not be…but, they may just generally not have the same issues with nonuniform cooling and it may not be needed, hard to know.

 

[MP3Mike]

they ran very thin cooling strips between every other row of cells, not huge ones for every single cell

The 4680 pack uses the same setup, thin cooling tubes down every other row of cells... I have no idea what "huge ones for every single cell" is that you are talking about.

 

[AlanSubie4Life]

The 4680 pack uses the same setup, thin cooling tubes down every other row of cells... I have no idea what "huge ones for every single cell" is that you are talking about.

Yeah doesn’t sound like a lot of cogent analysis here. I’m fine with the hypothesis that the new cell is not that much better but having actual facts to back that up would be nice to have, if that is the theory.

Snakes every other cell row likely means better inherent cooling properties of the 4680 if they are able to get away with that, though. And lower overhead (depending on the thickness of the snake), potentially. (Modify formulas above accordingly.)

 

[Resist]

I know this is amazing for manufacturing but it seems to me if your car ever needs a new battery pack then instead of just dropping the battery and replacing it, now the service center has to unbolt and bolt back in the seats, center console and carpet. This creates so many opportunities for them to screw things up.

 

[evphile]

I know this is amazing for manufacturing but it seems to me if your car ever needs a new battery pack then instead of just dropping the battery and replacing it, now the service center has to unbolt and bolt back in the seats, center console and carpet. This creates so many opportunities for them to screw things up.

That is a fair point, but perhaps TESLA’s pursuit of the ever-elusive “million mile battery pack” has finally paid off and they are not anticipating having to replace any of the 4680 cell packs.

 

[AlanSubie4Life]

I know this is amazing for manufacturing but it seems to me if your car ever needs a new battery pack then instead of just dropping the battery and replacing it, now the service center has to unbolt and bolt back in the seats, center console and carpet. This creates so many opportunities for them to screw things up.

Apparently you haven’t seen the current removal method?

Not the exact optimal method but you get the idea.

 

[evphile]

Apparently you haven’t seen the current removal method?

Not the exact optimal method but you get the idea.

This is a Model 3 battery pack featured in the video you posted. In this thread, we’ve been discussing the removal of the new 4680 structural battery pack installed in many of the brand new Model Y’s. Check out the “Munro Live” video recently uploaded to YouTube by Munro & Assoc., which shows the Model Y seat risers bolted and welded directly to the top of the 4680 structural battery pack.