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.

 

[MP3Mike]

I don’t see how 816 is possible if all the modules are the same.

That would be 204 per module, which is fine in theory.

But 816 has to be 102s8p (unless they went to a very high voltage pack, 136s6p, which seems extremely unlikely).

Yep, they probably just counted the outside row of cells and multiplied. What they forgot is that the displays at GigaTexas showed that every other row has one extra cell. So that adds 12 cells, which puts as exactly at the 828 cells that Tesla showed on display that everyone thought was for the LR pack.

I am not sure we can tell from the number of cells how many real cells there are though. Obviously there are only so many possibilities and looking at the connecting structure (which may be possible from the video but no time) would eliminate some.

Yep. We now know, IMO, that there are 828 cell cans, now we need to know how many of them are actual real cells.

 

[ZenRockGarden]

I don’t see how 816 is possible if all the modules are the same.

That would be 204 per module, which is fine in theory.

But 816 has to be 102s8p (unless they went to a very high voltage pack, 136s6p, which seems extremely unlikely).

So if all the modules are the same that 102s is not divisible by 4. And obviously each module is not 102s2p; the BMBs are relatively low voltage.

828 would be a lower voltage pack (92s9p) (92/4 = 23 per module) which is arguably unfortunate. Thicker wires. And theoretically slower charging depending on charger current limits. Small differences though.

I am not sure we can tell from the number of cells how many real cells there are though. Obviously there are only so many possibilities and looking at the connecting structure (which may be possible from the video but no time) would eliminate some.

It’s probably possible to reason through the depop options and figure out which ones are possible, but have not bothered. It seems like depop would be easiest by just removing a parallel string and leaving number of series the same. (So 23 at a time per module, for example, could take the pack to 736, 92s8p, 4x 23s8p)

We’ll know soon enough! I’m sure someone has already figured it out without looking.

That battery-management-module at the top of each stack looks like it may be covering the area of an unknown number of cells...

 

[ZenRockGarden]

Yep, they probably just counted the outside row of cells and multiplied. What they forgot is that the displays at GigaTexas showed that every other row has one extra cell. So that adds 12 cells, which puts as exactly at the 828 cells that Tesla showed on display that everyone thought was for the LR pack.



Yep. We now know, IMO, that there are 828 cell cans, now we need to know how many of them are actual real cells.

Yeah, if it's 828 (which looks like the best guess, and conveniently matches earlier display models) then we almost have to be in a situation where Tesla is trying to make a full-size pack layout and has gone with some empty cells to create the down-rated MYAWD example of it. That'd give the observed lower voltage and KWh totals.

The fun implication of that is they could pretty rapidly make a LR pack if they wanted to.

 

[MP3Mike]

That'd give the observed lower voltage and KWh totals.

What is the observed voltage? (I haven't seen that reported yet.)

 

[ZenRockGarden]

What is the observed voltage? (I haven't seen that reported yet.)

I'm assuming it's there due to the lower 0-60 on otherwise identical motors. I suppose you could also have current-limited the thing, so yeah I shouldn't directly claim voltage.

 

[AlanSubie4Life]

Yep. We now know, IMO, that there are 828 cell cans, now we need to know how many of them are actual real cells.

I’d guess 736, but that doesn’t align with the weight really. Even steel cans with some structure inside would be notably lighter than the cells, I assume, and 92 would add up. If it’s 828 I am not sure what Tesla was referring to recently when they discussed the lower capacity. (And it means they locked 10+kWh out of the EPA test.)

It’s all quite confusing (to me at least).

Also if empty cells have significant weight that’s kind of a disadvantage for lower range vehicles with a structural pack (wouldn’t save as much weight). Maybe they just don’t plan on many of those. Or maybe they can use a more efficient depopulation strength retention method for more extensive depopulation.

I'm assuming it's there due to the lower 0-60 on otherwise identical motors.

It’s been a while since I have looked at this, so forgive me for any imprecision, but do you have some evidence that the pack is the limiting factor for acceleration and 0-60? Pretty sure in non-P they just impose a motor power limit. That’s my recollection anyway. A link to the many people who have done full data capture on this, showing I am misremembering, would suffice.

Plus it takes nearly zero power to launch incredibly quickly, so where did the discrepancy on the 0-60 show up? You’d expect no difference at low speeds assuming they can dump the required current. Requires very little from the pack (other than a lot of current).

I wouldn’t be surprised at any number of artificial limits imposed on a new pack which limit the demands on the pack and the 0-60, unrelated to max pack voltage.

Note I am not saying the pack voltage is not lower (it seems likely that it is). Just saying that I think it is hard to conclude anything based on 0-60 times, at this time.

 

[ZenRockGarden]

I’d guess 736, but that doesn’t align with the weight really. Even steel cans with some structure inside would be notably lighter than the cells, I assume, and 92 would add up. If it’s 828 I am not sure what Tesla was referring to recently when they discussed the lower capacity. (And it means they locked 10+kWh out of the EPA test.)

It’s all quite confusing (to me at least).

Also if empty cells have significant weight that’s kind of a disadvantage for lower range vehicles with a structural pack (wouldn’t save as much weight). Maybe they just don’t plan on many of those. Or maybe they can use a more efficient depopulation strength retention method for more extensive depopulation.


It’s been a while since I have looked at this, so forgive me for any imprecision, but do you have some evidence that the pack is the limiting factor for acceleration and 0-60? Pretty sure in non-P they just impose a motor power limit. That’s my recollection anyway. A link to the many people who have done full data capture on this, showing I am misremembering, would suffice.

Plus it takes nearly zero power to launch incredibly quickly, so where did the discrepancy on the 0-60 show up? You’d expect no difference at low speeds assuming they can dump the required current. Requires very little from the pack (other than a lot of current).

I wouldn’t be surprised at any number of artificial limits imposed on a new pack which limit the demands on the pack and the 0-60, unrelated to max pack voltage.

Note I am not saying the pack voltage is not lower (it seems likely that it is). Just saying that I think it is hard to conclude anything based on 0-60 times, at this time.

MYP uses an uprated rear motor for what I think is more launch torque by allowing higher current at the fixed max voltage. If you put acceleration-boost on a MYLR it's actually pretty close (and thus just the max output of the pack) at higher speeds.

We know the MYAWD is slower by a half second or so. It has identical motors. The only thing that's different IS the pack, hence I expect that's what matters.

Fun topic. We will certainly learn more.

 

[Resist]

So I guess with the new 4680 battery pack, it's impossible to repair should a module go bad. Seems like a waste to me, and a huge compromise to make it part of the structural integrity. I mean it's great for manufacturing but not for the consumer. Looks like Tesla will save money with this new pack but isn't passing any of it down to the consumer. No increased range and no lowered car price, so where is the benefit for us?

 

[MP3Mike]

So I guess with the new 4680 battery pack, it's impossible to repair should a module go bad. Seems like a waste to me, and a huge compromise to make it part of the structural integrity. I mean it's great for manufacturing but not for the consumer. Looks like Tesla will save money with this new pack but isn't passing any of it down to the consumer. No increased range and no lowered car price, so where is the benefit for us?

It is no different than any other pack Tesla has made. If a module goes bad you replace the pack.

 

[AndrewZ]

Speaking of replacing the pack, am I thinking the wrong way here or does this structural pack not look a lot more complicated to replace than the regular battery packs?

With the structural pack forming basically the entire cabin floor and having the front seats and such attached, switching out the pack will involve detaching things from the original pack and putting them on the replacement?

Previous articles (InsideEV, Electrek) talking about the service manual excerpts said it was 314 steps to replace the pack, I’m guessing much of that is the swapping. This seems really good from a manufacturing standpoint but problematic in servicing, with each step introducing a new opportunity for human error. Unless the idea is to have replacement packs ready to slide in with all new seats, new hardware, etc, then it would be a totally different story.


Anyways I’m sure the gain in ease of manufacturing is a net win for Tesla

 

[Resist]

It is no different than any other pack Tesla has made. If a module goes bad you replace the pack.

Not true. Before a module could be replaced from the pack. Now it isn't possible.

 

[Resist]

Speaking of replacing the pack, am I thinking the wrong way here or does this structural pack not look a lot more complicated to replace than the regular battery packs?

With the structural pack forming basically the entire cabin floor and having the front seats and such attached, switching out the pack will involve detaching things from the original pack and putting them on the replacement?

Previous articles (InsideEV, Electrek) talking about the service manual excerpts said it was 314 steps to replace the pack, I’m guessing much of that is the swapping. This seems really good from a manufacturing standpoint but problematic in servicing, with each step introducing a new opportunity for human error. Unless the idea is to have replacement packs ready to slide in with all new seats, new hardware, etc, then it would be a totally different story.


Anyways I’m sure the gain in ease of manufacturing is a net win for Tesla

I've said this exact same thing! Replacing a pack with involve removing more bolts/screws now than before and just is more things service people can screw up.

 

[MP3Mike]

Not true. Before a module could be replaced from the pack. Now it isn't possible.

Sure, while you could physically replace the module, it wouldn't actually fix the pack. It would fail again in as little as a day of driving. (Unless you could magically find a module that matched the others exactly, which even Tesla wasn't able to do so they stopped trying to replace modules.)

I've said this exact same thing! Replacing a pack with involve removing more bolts/screws now than before and just is more things service people can screw up.

Sure, it requires a few more bolts, but not actually that many more. (You already have to remove a bunch of the interior on the Model 3/Y to get to the bolts necessary to drop the 2170 based packs.)

 

[sleepydoc]

Speaking of replacing the pack, am I thinking the wrong way here or does this structural pack not look a lot more complicated to replace than the regular battery packs?

With the structural pack forming basically the entire cabin floor and having the front seats and such attached, switching out the pack will involve detaching things from the original pack and putting them on the replacement?

Previous articles (InsideEV, Electrek) talking about the service manual excerpts said it was 314 steps to replace the pack, I’m guessing much of that is the swapping. This seems really good from a manufacturing standpoint but problematic in servicing, with each step introducing a new opportunity for human error. Unless the idea is to have replacement packs ready to slide in with all new seats, new hardware, etc, then it would be a totally different story.


Anyways I’m sure the gain in ease of manufacturing is a net win for Tesla

I've said this exact same thing! Replacing a pack with involve removing more bolts/screws now than before and just is more things service people can screw up.

Watch Sandy Munro’s video on removing the structural pack. He says it’s actually a bit easier. Regardless, replacing a battery pack is like replacing an engine. It’s a rare event that you should be able to do but it makes no sense to worry about the efficiency of the task or spend time optimizing it. The manufacturing costs will be far more relevant.

 

[Resist]

Watch Sandy Munro’s video on removing the structural pack. He says it’s actually a bit easier. Regardless, replacing a battery pack is like replacing an engine. It’s a rare event that you should be able to do but it makes no sense to worry about the efficiency of the task or spend time optimizing it. The manufacturing costs will be far more relevant.

I've watched the video. Yes, removing the pack is easier but as I've said, now the seats and console and carpet also have to be removed and reinstalled on the new pack. That's a lot of bolts and things that can be missed or scratched with the reinstall. Heck, when Tesla had to replace the high voltage cable in my Model 3 years ago, they scratched the plastic in my rear seats and my new rear cargo mat. Often techs aren't as careful as they should be with other people's vehicles.

 

[MP3Mike]

Yes, removing the pack is easier but as I've said, now the seats and console and carpet also have to be removed and reinstalled on the new pack.

The seats have to be removed to replace a non-structural pack as well... I'm not sure about the console.

 

[Resist]

The seats have to be removed to replace a non-structural pack as well... I'm not sure about the console.

I had the understanding that with non-structural battery packs, the entire pack can just be dropped down leaving the seats and flooring in place in the car. In fact Tesla had considered battery pack replacements as an option to charging, while you are in the car and it could be done faster than filling up a car with gas. They even showed a video doing it.

 

[MP3Mike]

I had the understanding that with non-structural battery packs, the entire pack can just be dropped down leaving the seats and flooring in place in the car. In fact Tesla had considered battery pack replacements as an option to charging, while you are in the car and it could be done faster than filling up a car with gas. They even showed a video doing it.

That was true with the original S&X, but they gave up on that starting with the 3.

It takes about 4 hours to remove and replace the pack on a Model 3 or Model Y.

 

[ucmndd]

I had the understanding that with non-structural battery packs, the entire pack can just be dropped down leaving the seats and flooring in place in the car. In fact Tesla had considered battery pack replacements as an option to charging, while you are in the car and it could be done faster than filling up a car with gas. They even showed a video doing it.

 

[Resist]

That was true with the original S&X, but they gave up on that starting with the 3.

It takes about 4 hours to remove and replace the pack on a Model 3 or Model Y.

Okay, didn't know that. Thanks for the info!

Now I shudder at the thought of my battery pack ever needing to be replaced. The disassembly and reassembly looks like a nightmare. No doubt there would be missing bolts everywhere or some line not connected properly.