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.

 

[AlanSubie4Life]

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.

I am obviously well aware of that video.
I was commenting on this:

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.

The removal method of the 2170 pack is presumably similar on the 2170 Y as it is to the 3…or did they make it ultra simple (no bolts in the interior of the car) when I wasn’t paying attention?

I thought it was basically the same common part so I assume it attaches the same way on the Model 3 and Model Y.

My point was that significant portions of the interior (perhaps not as many as in the non-optimal video above but I am not sure what the minimum amount is as I have not done this myself) have to be removed to just get the battery out of a 2170 vehicle. So there’s minimal “savings” with the 2170 pack vs. a 4680 removal. In fact, if you don’t actually replace the pack (seems like an unlikely scenario - you’d always replace it presumably), then there are probably fewer steps to remove and reinstall the same 4680 pack than to do the same with a 2170 (because you can leave the seats where they are with 4680).

I’d like to think you could just lift up a bit of carpet and unbolt a few bolts in the interior of a 2170 Y to allow the battery to drop (that would have been smart!) but I don’t think that is the case.

 

[Resist]

I’d like to think you could just lift up a bit of carpet and unbolt a few bolts in the interior of a 2170 Y to allow the battery to drop (that would have been smart!) but I don’t think that is the case.

It's more than just a few bolts to remove the seats, console and carpet. As it is now service departments alway seem to forget bolts and electrical connections. Adding more into the mix will just make things worse. And it's the same with the castings.

 

[AlanSubie4Life]

It's more than just a few bolts to remove the seats, console and carpet.

Exactly, which was my point.

 

[advocate8]

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).

There’s no engineering reason to add heavy material to obtain the structural advantages needed from the pack. Sandwich construction, which is wheat this is, is pretty straightforward approach in the composites world. The gains are in using light material, sometimes in structural shapes (think honeycomb) to hold the top and bottom skins in the same positions relative to each other. Most of the strength of sandwich is from the shape, especially the thickness, rather than the amount or density of material used.

 

[AlanSubie4Life]

There’s no engineering reason to add heavy material to obtain the structural advantages needed from the pack. Sandwich construction, which is wheat this is, is pretty straightforward approach in the composites world. The gains are in using light material, sometimes in structural shapes (think honeycomb) to hold the top and bottom skins in the same positions relative to each other. Most of the strength of sandwich is from the shape, especially the thickness, rather than the amount or density of material used.

Yeah I’d expect any placeholders to be lighter than the cells they stand in for.

It’ll be interesting to see how this is done - will give an idea of how much the cells are actually relied on for structure.

 

[sleepydoc]

So I just watched the battery day presentation again. There's some handwaving going on and also some things that aren't necessarily deceptive but that people are interpreting incorrectly.

They talked about 5x the energy. This is strictly a volume calculation. At the beginning of the video they take about 2170 batteries having 50% more energy than 1865 batteries, then later on they talk about the 4680 batteries having 5x the energy. If you calculate the volume of the batteries you get 16.5 cm3, 24.2 cm3 and 133 cm3 for the 1865, 2170 and 4680 batteries, respectively. Note that the 2170 has 50% more volume than the 1865 and the 4580 is just over 5x the volume of the 2170.

The other 2 numbers mentioned, 16x range and 6x the power are really hard to interpret. Range is a matter of energy stored and vehicle efficiency. A battery doesn't give more range in and of itself. Likewise, power is energy per unit time, or speed of energy usage, not total energy. Saying a battery has 6x the power really only means you can empty it faster, it doesn't necessarily mean it has any more energy. The other thing they talked about with the tabless design was a 5x reduction in the electrical path in the battery. My take from this is that the internal resistance of the battery is significantly lower, decreasing heating and power loss in the battery. This increases the efficiency of the battery and could potentially allow higher peak currents (=power) or longer range due to decreased thermal losses but they never explicitly state that.

Of note, there was virtually no mention of increased energy density. They did discuss using silicon electrodes which may have some potential but everything else in the talk implied that the density was the same. In some ways a lager cell is worse because you can't pack it as tight in the battery pack, but that ignores heat and other considerations. Regardless, any weight savings would primarily be realized via the battery pack structure, not the batteries themselves.

A significant portion of what they discussed was related to manufacturing efficiencies, decreased manufacturing costs and cost per watt-hour. This make sense for an investor meeting but won't be directly visible to a consumer. There's also a lot of capital outlay for both the research and the manufacturing infrastructure. That combined with the current automobile market makes me doubt we'll see a change anytime soon.

Finally, a few quotes that stuck out for me:

• "power to weight ratio is actually better than in the smaller cell with tabs" - note they say power, not energy. Energy to weight is energy density. Power to weight is peak current.
• Elon “And just to clarify, when we see these plus 16% or whatever the percentage rate increase is, these are the amounts due just to that particular innovation. So we'll list a whole bunch of innovations and then when you add them up, you get a total improvement in energy density and cost. But these numbers are what refer to just this thing.” - here he actually says energy density but nothing else in the talk mentioned this that I heard
• Elon: “ to be clear, I would like to not say that right now, it just totally working. It's close to working, but it's not, even now at the pilot plant level, it is close to working. It's fair to say probably it does work, but with not a good, not a high yield.” “There's a clear path to success, but a ton of work between here and there.”
• Drew Baglino: “by leveraging this silicon to its potential, we can increase the range of our vehicles by an additional 20%. Just this improvement.”
• Elon: “So what this enables us to do is achieve a new trajectory in the reduction of cell cost. And now to be clear, it will take us probably a year to 18 months to start realizing these advantages and to fully realize the advantages probably it's about three years or thereabouts.”

Again, range is total battery energy divided by efficiency. They threw 'range' out several times but it wasn't clear where it was coming from. my guess is a combination of increased battery efficiency and potential increases in energy density with the silicon electrode, once it's developed.

 

[AlanSubie4Life]

16x

16%

there was virtually no mention of increased energy density.

There was. Earlier here (in this thread I think, not sure) there’s a slide that shows the breakdown of how they got to the 54% total (16% cell change, 14% pack integration (notably matches the ratio of 80/70; not sure if a coincidence), 24% from anode/cathode).

That last one is energy density improvement. I doubt it applies to the current cells in any significant way though. They’d need to be more conservative with that.

In some ways a lager cell is worse because you can't pack it as tight in the battery pack

Not fundamentally, except for edge effects (which yes, are significant). And a large redesigned cell which has more uniform heat transfer might well be able to be packed more tightly due to more space-efficient cooling structure. We’ll see. Looks marginally better at the current time but we need the measurements.

 

[advocate8]

So I just watched the battery day presentation again. There's some handwaving going on and also some things that aren't necessarily deceptive but that people are interpreting incorrectly.

They talked about 5x the energy. This is strictly a volume calculation. At the beginning of the video they take about 2170 batteries having 50% more energy than 1865 batteries, then later on they talk about the 4680 batteries having 5x the energy. If you calculate the volume of the batteries you get 16.5 cm3, 24.2 cm3 and 133 cm3 for the 1865, 2170 and 4680 batteries, respectively. Note that the 2170 has 50% more volume than the 1865 and the 4580 is just over 5x the volume of the 2170.

The other 2 numbers mentioned, 16x range and 6x the power are really hard to interpret. Range is a matter of energy stored and vehicle efficiency. A battery doesn't give more range in and of itself. Likewise, power is energy per unit time, or speed of energy usage, not total energy. Saying a battery has 6x the power really only means you can empty it faster, it doesn't necessarily mean it has any more energy. The other thing they talked about with the tabless design was a 5x reduction in the electrical path in the battery. My take from this is that the internal resistance of the battery is significantly lower, decreasing heating and power loss in the battery. This increases the efficiency of the battery and could potentially allow higher peak currents (=power) or longer range due to decreased thermal losses but they never explicitly state that.

Of note, there was virtually no mention of increased energy density. They did discuss using silicon electrodes which may have some potential but everything else in the talk implied that the density was the same. In some ways a lager cell is worse because you can't pack it as tight in the battery pack, but that ignores heat and other considerations. Regardless, any weight savings would primarily be realized via the battery pack structure, not the batteries themselves.

A significant portion of what they discussed was related to manufacturing efficiencies, decreased manufacturing costs and cost per watt-hour. This make sense for an investor meeting but won't be directly visible to a consumer. There's also a lot of capital outlay for both the research and the manufacturing infrastructure. That combined with the current automobile market makes me doubt we'll see a change anytime soon.

Finally, a few quotes that stuck out for me:

• "power to weight ratio is actually better than in the smaller cell with tabs" - note they say power, not energy. Energy to weight is energy density. Power to weight is peak current.
• Elon “And just to clarify, when we see these plus 16% or whatever the percentage rate increase is, these are the amounts due just to that particular innovation. So we'll list a whole bunch of innovations and then when you add them up, you get a total improvement in energy density and cost. But these numbers are what refer to just this thing.” - here he actually says energy density but nothing else in the talk mentioned this that I heard
• Elon: “ to be clear, I would like to not say that right now, it just totally working. It's close to working, but it's not, even now at the pilot plant level, it is close to working. It's fair to say probably it does work, but with not a good, not a high yield.” “There's a clear path to success, but a ton of work between here and there.”
• Drew Baglino: “by leveraging this silicon to its potential, we can increase the range of our vehicles by an additional 20%. Just this improvement.”
• Elon: “So what this enables us to do is achieve a new trajectory in the reduction of cell cost. And now to be clear, it will take us probably a year to 18 months to start realizing these advantages and to fully realize the advantages probably it's about three years or thereabouts.”

Again, range is total battery energy divided by efficiency. They threw 'range' out several times but it wasn't clear where it was coming from. my guess is a combination of increased battery efficiency and potential increases in energy density with the silicon electrode, once it's developedeithsr they’

16%

There was. Earlier here (in this thread I think, not sure) there’s a slide that shows the breakdown of how they got to the 54% total (16% cell change, 14% pack integration (notably matches the ratio of 80/70; not sure if a coincidence), 24% from anode/cathode).

That last one is energy density improvement. I doubt it applies to the current cells in any significant way though. They’d need to be more conservative with that.

Not fundamentally, except for edge effects (which yes, are significant). And a large redesigned cell which has more uniform heat transfer might well be able to be packed more tightly due to more space-efficient cooling structure. We’ll see. Looks marginally better at the current time but we need the measurements.

You’re being too generous.

either they’re geniuses and were being intentionally vague to boost the hype machine…(seriously..if you’re tgat smart you can convey ideas much better than that) or they’re not geniuses. Best bet is they are geniuses.

 

[AlanSubie4Life]

Not sure what you wrote here (quoting issue it looks like) but also not sure how I am being too generous.
I’m not the least bit interested in giving credit anyway. Just interested in these packs and what their specs will be. And trying to align with their prior representations and compare.

 

[AlanSubie4Life]

Super boring teardown of a cell:

Watch Tesla's 4680-Type Cylindrical Battery Cell Teardown

Here is a very interesting video of a Tesla 4680-type cylindrical battery cell teardown, presented by The Limiting Factor.

insideevs.com

I couldn't bear to watch the video, so maybe I missed it, but I don't think they even ran the cell through a tester first to determine the capacity!!! Arrggh. Sticking with the expected 100Wh for now.

 

[MP3Mike]

but I don't think they even ran the cell through a tester first to determine the capacity!!!

It was an early production cell that was dented, so they didn't want to charge it and risk having bad things happen.

 

[ZenRockGarden]

As we get closer to Munro actually showing us the 4680 packs cylinders and giving us details on cell count, total capacity, cooling etc. Remember that back in the battery-day era, the expectation was that "the 4680" was gonna look something like this (note - bottom-only plate cooling, no snake-pipes, no foam, max cylinder density):

https://i0.wp.com/electrek.co/wp-content/uploads/sites/3/2020/07/Tesla-Panasonic-battery-cells.jpg?w=2500&quality=82&strip=all&ssl=1

I think the "wall" they hit on making a fully functional 4680 pack was a thermal one - plate cooling wasn't enough, and the re-do with a scaled-up version of snake cooling mostly cancelled all the expected gains for pack density.

They may get it sorted out in the future. I hope so. But expect a lot less cylinders when Munro scrapes off the pink goo.

 

[MP3Mike]

Remember that back in the battery-day era, the expectation was that "the 4680" was gonna look something like this (note - bottom-only plate cooling, no snake-pipes, no foam, max cylinder density):

https://i0.wp.com/electrek.co/wp-content/uploads/sites/3/2020/07/Tesla-Panasonic-battery-cells.jpg?w=2500&quality=82&strip=all&ssl=1
I think the "wall" they hit on making a fully functional 4680 pack was a thermal one - plate cooling wasn't enough, and the re-do with a scaled-up version of snake cooling mostly cancelled all the expected gains for pack density.

That wasn't everyone's expectation, and shouldn't have been. I fully expected the ribbon cooling pipes as well as the foam in place. (And filler for the smaller packs that aren't 100% filled with cells.) So it seems to me that they are exactly on track.

Also, they didn't say that the first cells/packs out would have all of the advancements that they are working on. (I think they said most of them would be in production by the end of 2025.) I fully expect more cathode/anode advancements to come.

 

[AlanSubie4Life]

They may get it sorted out in the future. I hope so. But expect a lot less cylinders when Munro scrapes off the pink goo.

I expect either 672, or 768 cylinders (actual cells). The weight makes me think 768, while the apparent capacity of 70kWh (maybe there is more there but that sort of lockout would be unusual) makes me think 672.

Munro said something about “around 800.”

Anyway we’ll see. Something doesn’t quite add up to me at the moment. Pack appears to be too low capacity for the alleged weight of the vehicle (which has allegedly been confirmed). Hopefully will become apparent soon enough.

No one has hooked up SMT I guess?

 

[ZenRockGarden]

That wasn't everyone's expectation, and shouldn't have been. I fully expected the ribbon cooling pipes as well as the foam in place. (And filler for the smaller packs that aren't 100% filled with cells.) So it seems to me that they are exactly on track.

Also, they didn't say that the first cells/packs out would have all of the advancements that they are working on. (I think they said most of them would be in production by the end of 2025.) I fully expect more cathode/anode advancements to come.

I hear you, but it IS an "expectation" built into the chain of assumptions for those insisting in mythical "500 mile LR packs being driven around by employees" and "software locked additional 50% capacity" as well as guesses on cell count in the 800 and 900 region.

 

[farmerj]

Less weight and cheaper production costs come to mind.

Have only seen one reference comparing "regular" dual motor with the 4680... no idea if it's correct but the weight savings were not at all impressive (so far?), and I think the capacity of these packs is less than the standard dual motor. So far, seems "reduction in capital expenditure" for tesla is about it. Wish someone would compare curb weights again and verify.

 

[acarney]

I also think thermal issues will be the hardest to overcome. Haven't we already seen that the 4680 packs charge much slower right now in the real world? I know Tesla has a habit of easing into things and then unlocking more in software, but they've been working on these cells for awhile and have a lot of data from existing cell and pack designs. I would think, even if it's a completely different design, they would have a quicker curve to build the confidence compared to before. I mean 2170 cells started out performing better than the S/X with their 18650.

That's going to be a lot of mass to keep cool (or be confident they can run hot) when dumping 250 to 300kW (or more) of power into them. It would be nice if they could come up with a thermal paste that was also a fire barrier and use that around the cells so they could utilize their entire surface area to dissipate heat. Still need to remove that heat from the back, but you have more of a solid "block" of heat rather than each cell being a hot spot.

 

[AlanSubie4Life]

they would have a quicker curve to build the confidence compared to before

No, there’s basically all downside to that for Tesla and no upside. Just take it easy.

 

[uscbucsfan]

I mean 2170 cells started out performing better than the S/X with their 18650.

In what way? Maybe the older 2170s, but it doesn't appear that way in the new ones.

 

[acarney]

In what way? Maybe the older 2170s, but it doesn't appear that way in the new ones.

I think when 2170s hit with the Model 3 they quickly (like within six months) were able to charge at V3 speeds while the 18650s were limited to ~200kW (and that I think even took awhile before Tesla software upgraded them).

I think the Plaid refresh was the first time S/X was actually advertised and allowed to go all the way to V3 (250kW) speeds...