# Is the 4680 a failure for Tesla



## Madmolecule (Oct 8, 2018)

What’s going on with the 4680. All I read our excuses and alternative plans to build vehicles with the older batteries. I thought the 4680 structural battery pack was going to solve all problems, reduce price, extend range.

What is going on? Is it poor engineering, design or lack of quality talent in regulation free Texas.


----------



## garsh (Apr 4, 2016)

The dry cathode technology is new - it's never been done before. This is the part of the process that will massively reduce cost of production. It's taking them longer than expected to get production yields to acceptable levels.



Madmolecule said:


> I thought the 4680 structural battery pack was going to solve all problems, reduce price, extend range.


Primarily, reduce cost.


----------



## shareef777 (Mar 10, 2019)

garsh said:


> The dry cathode technology is new - it's never been done before. This is the part of the process that will massively reduce cost of production. It's taking them longer than expected to get production yields to acceptable levels.
> 
> Primarily, reduce cost.


Thought it also provided more energy/kg.


----------



## garsh (Apr 4, 2016)

shareef777 said:


> Thought it also provided more energy/kg.


A little bit - less weight dedicated to the cell casing and a floor in the vehicle.
The tabless design permits faster charging and reduces hot spots in each cell.

But the dry cathode step is by far the most difficult change to implement, and has the biggest payoff if/when they're successful.


----------



## bwilson4web (Mar 4, 2019)

I’m partial to the Munro YouTube on the 4680:





They also have sell a detailed technical report on the 4680.

Bob Wilson


----------



## Ed Woodrick (May 26, 2018)

Madmolecule said:


> What’s going on with the 4680. All I read our excuses and alternative plans to build vehicles with the older batteries. I thought the 4680 structural battery pack was going to solve all problems, reduce price, extend range.
> 
> What is going on? Is it poor engineering, design or lack of quality talent in regulation free Texas.


If you thought that it was going to solve all of the above, then you need to reset your dreams. Never was expected to do all that


----------



## JasonF (Oct 26, 2018)

The only reason for the 4680's existence is to solve common battery production issues. Tabs are a bottleneck to the assembly process for all batteries, so 4680's are tabless. They're a larger size around, and slightly higher energy density, which means fewer of them are required in a single vehicle's battery pack for the same amount of kWh, reducing the amount of production time that has to go into each battery pack.

Gluing the batteries in, cooling them efficiently, and making the a structural part of the car are related to car production more so than battery pack production.

But the reason I separated the two is because they're very much two separate things to solve. First Tesla has to be able to produce 4680's quickly enough, and with as few rejects as possible. They have not mastered that part, and the 4680's are therefore being produced in too small a volume to put into every one of a particular model produced. This is by far the most alarming issue, because it means they designed vehicles around the success of a process that some companies that make nothing but batteries take decades to master.

And because that's still an issue, it also raises an issue with the structural packs and bodies, because if they can't master the battery production fast enough Tesla could end up with molds and presses that become outdated before they're ever used for production.

So to answer the thread title, they're not a failure...yet. Hopefully they won't become one.


----------



## francoisp (Sep 28, 2018)

Maybe technology is moving fast making the 4680 obsolete before it's even released.


----------



## tivoboy (Mar 24, 2017)

francoisp said:


> Maybe technology is moving fast making the 4680 obsolete before it's even released.


Probably not. The only thing near term that could threaten 4680 would probably be some solid state offering, but I think that is still probably 3-5 years out from some large scale adoption.. solution and adoption.


----------



## bwilson4web (Mar 4, 2019)

The 4680 form factor does a good job of maximum active battery chemicals with a small surface volume and structural housing. This is just an optimum package that minimizes other pack and car parts … multiple uses.

The battery chemistry can vary as needed. With possible exception of chemistry that has substantial volume change between charged and discharged, I don’t see an incompatibility with the 4680 form factor. Even large changes in volume can be handled within the form factor.

Bob Wilson


----------



## francoisp (Sep 28, 2018)

bwilson4web said:


> The 4680 form factor does a good job of maximum active battery chemicals with a small surface volume and structural housing. This is just an optimum package that minimizes other pack and car parts … multiple uses.
> 
> The battery chemistry can vary as needed. With possible exception of chemistry that has substantial volume change between charged and discharged, I don’t see an incompatibility with the 4680 form factor. Even large changes in volume can be handled within the form factor.
> 
> Bob Wilson


Seems to me that a pouch or blade system is even better at maximizing volume because there aren't any gaps like between cylinders.


----------



## garsh (Apr 4, 2016)

francoisp said:


> Seems to me that a pouch or blade system is even better at maximizing volume because there aren't any gaps like between cylinders.


There are gaps in blades - they're just internal to the case instead of external like a cylindrical.

The first gaps are at the edges where the jellyroll has to bend around from top to bottom.
But the biggest gap is down the middle of the cell. You can't just have the cathode bend 180° in that first layer, so there will be a sizable gap.
The benefit of cylindricals is that the middle gap is only a little "rod" instead of the huge cuboid gap found in a blade.










It's even worse for pouch cells. The reason they're pouches is to allow for expansion. That means you have to allow expansion space between the pouches.


----------



## Madmolecule (Oct 8, 2018)

Tesla heralds future miracles with great specificity ( ie the bots weight, roadster 0-60). When they get real quiet on something, it usually means it has failed to live up to the Kickstarter dream.

I will prove my point in just a couple weeks with the Semi. I just have a simple question on their 500 mile fully loaded claim, how much cargo can you carry for 500 miles?

Not Elon (or parody this stopped being funny a while ago)


----------



## francoisp (Sep 28, 2018)

Madmolecule said:


> Tesla heralds future miracles with great specificity ( ie the bots weight, roadster 0-60). When they get real quiet on something, it usually means it has failed to live up to the Kickstarter dream.
> 
> I will prove my point in just a couple weeks with the Semi. I just have a simple question on their 500 mile fully loaded claim, how much cargo can you carry for 500 miles?
> 
> Not Elon (or parody this stopped being funny a while ago)


This question has been answered (granted using some educated guests) by Engineering Explained.


----------



## francoisp (Sep 28, 2018)

garsh said:


> There are gaps in blades - they're just internal to the case instead of external like a cylindrical.
> 
> The first gaps are at the edges where the jellyroll has to bend around from top to bottom.
> But the biggest gap is down the middle of the cell. You can't just have the cathode bend 180° in that first layer, so there will be a sizable gap.
> ...


Interesting. However how do you know there's bending in every type of pouch or blade out there? I mean these layers could simply be staked without bends. And what about the gaps between each round cell? Sounds like wasted space to me.


----------



## bwilson4web (Mar 4, 2019)

francoisp said:


> Interesting. However how do you know there's bending in every type of pouch or blade out there? I mean these layers could simply be staked without bends. And what about the gaps between each round cell? Sounds like wasted space to me.


I have no problem with running coolant through those spaces.

Bob Wilson


----------



## francoisp (Sep 28, 2018)

bwilson4web said:


> I have no problem with running coolant through those spaces.
> 
> Bob Wilson


With the new structural battery I do not believe coolant flows that way at least based on a Munroe video showing the glue binding the cells.


----------



## Klaus-rf (Mar 6, 2019)

Madmolecule said:


> I just have a simple question on their 500 mile fully loaded claim, how much cargo can you carry for 500 miles?


 I heard at least a couple cases of Pepsi.


----------



## garsh (Apr 4, 2016)

francoisp said:


> Interesting. However how do you know there's bending in every type of pouch or blade out there? I mean these layers could simply be staked without bends.


If you just stack them, then you no longer have a cell - you (probably, if you do it correctly) have a stack of cells - aka, a "battery".

Then you have a bunch of cells in the middle of your stack that you can't monitor or isolate from the others if it were to fail.


> And what about the gaps between each round cell? Sounds like wasted space to me.


Sure, it is. I'm just pointing out that the other formats aren't solving that particular issue.
The one benefit of cylindricals is that you can stagger them to reduce the wasted space between them.


----------



## shareef777 (Mar 10, 2019)

Klaus-rf said:


> I heard at least a couple cases of Pepsi.


I assume you mean cases of the 7.5oz cans. Can't image the semi handling the full sized cans. That kind of power is being reserved for the CT.


----------



## JasonF (Oct 26, 2018)

francoisp said:


> With the new structural battery I do not believe coolant flows that way at least based on a Munroe video showing the glue binding the cells.


It does not, the coolant supposedly flows through plates above and beneath the batteries.


----------



## garsh (Apr 4, 2016)

JasonF said:


> It does not, the coolant supposedly flows through plates above and beneath the batteries.


I thought the original plan was to cool them from just a bottom plate. But IIRC, Munro's teardown shows that they're still cooling from the side.


----------



## bwilson4web (Mar 4, 2019)

francoisp said:


> With the new structural battery I do not believe coolant flows that way at least based on a Munroe video showing the glue binding the cells.


I agree with what Munro found. My speculation is the empty space between cells *could* flow coolant for thermal management.

Each cell would have three surfaces in contact with the coolant channels assuming staggered stacking. Four surfaces if inline stacking.

Bob Wilson


----------



## francoisp (Sep 28, 2018)

Madmolecule said:


> Tesla heralds future miracles with great specificity ( ie the bots weight, roadster 0-60). When they get real quiet on something, it usually means it has failed to live up to the Kickstarter dream.
> 
> I will prove my point in just a couple weeks with the Semi. I just have a simple question on their 500 mile fully loaded claim, how much cargo can you carry for 500 miles?
> 
> Not Elon (or parody this stopped being funny a while ago)


Looks like the semi can pull a full load for 500 miles 

Watch Tesla Semi do something Bill Gates said wasn't possible


----------



## shareef777 (Mar 10, 2019)

francoisp said:


> Looks like the semi can pull a full load for 500 miles
> 
> Watch Tesla Semi do something Bill Gates said wasn't possible


Absolutely amazing what the semi is capable of. Though I don't think it's using the 4680 cells.


----------



## garsh (Apr 4, 2016)

shareef777 said:


> Though I don't think it's using the 4680 cells.


What do you base that on?


----------



## shareef777 (Mar 10, 2019)

garsh said:


> What do you base that on?


It was reported a while back that Elon stated it wouldn't be using the 4680 cells. Things could have obviously changed, but figured they would have mentioned that if it did. Would be a huge milestone to have 4680 yield get high enough to support 50k semis annually, but don't think they're quiet there yet.









Tesla is aiming to ramp up to 50,000 Tesla Semi electric trucks per year


Tesla is aiming to ramp up Tesla Semi production to 50,000 electric trucks per year as soon as 2024 at Gigafactory Texas.




electrek.co


----------



## bwilson4web (Mar 4, 2019)

Some back of the envelope using:

1.7 kWh/mi on the 500 mi test trip
$135/kWh
7 mi/gal for $5/gallon diesel regular semi
Rough order of magnitude:

$115,000 battery cost
$0.20/mi electric cost
3.5 times cheaper to operate than an equivalent diesel
Bob Wilson


----------



## shareef777 (Mar 10, 2019)

bwilson4web said:


> Some back of the envelope using:
> 
> 1.7 kWh/mi on the 500 mi test trip
> $135/kWh
> ...


Just as it was in Tesla’s early days, the megacharger network will be key to the viability of Semi. Without a way to quickly charge, no one will buy one. As for the price, I’m sure it aligns well with billion dollar corporations that can install their own megacharger, but at 1.7kWh/mi the SC cost needs to be less than $.60/kWh and a regular v3 SC has rates that hit north of $.45 so this may not bode well for a large portion of semi drivers (owner/operators).


----------



## Rub"Y" (4 mo ago)

The truck was full of Frito chips.lol If you ever opened a bag of chips you know it's mostly air.


----------



## bwilson4web (Mar 4, 2019)

shareef777 said:


> but at 1.7kWh/mi the SC cost needs to be less than $.60/kWh and a regular v3 SC has rates that hit north of $.45 so this may not bode well for a large portion of semi drivers (owner/operators).


I suspect Tesla also makes grid level, storage systems that can significantly reduce their electricity costs. In times of electrical shortages, Tesla can even make money from their grid level battery systems. Regardless of our speculations, let's wait for more precise numbers. Perhaps in the next corporate reports?

Bob Wilson


----------



## garsh (Apr 4, 2016)

shareef777 said:


> Just as it was in Tesla’s early days, the megacharger network will be key to the viability of Semi.


I think Semi is going to see a different kind of supercharger rollout.

Fleet operators aren't going to use these for cross-country routes. At least not at first. They'll be deployed for regional uses that are within the 500 mile range. The fleet operators will have their own v4 superchargers and megapacks installed on-site for use by their own trucks.

It'll probably be 5-10 years before fleets start considering using these trucks for longer routes, and start requesting that Tesla establish v4's along the routes they use.


----------



## francoisp (Sep 28, 2018)

garsh said:


> It'll probably be 5-10 years before fleets start considering using these trucks for longer routes, and start requesting that Tesla establish v4's along the routes they use.


If the Semi is as good as it seems to be, I bet the roll out will be much faster that you anticipate. Competition will make sure of that.


----------



## garsh (Apr 4, 2016)

francoisp said:


> If the Semi is as good as it seems to be, I bet the roll out will be much faster that you anticipate. Competition will make sure of that.


I hope you're right.


----------



## francoisp (Sep 28, 2018)

garsh said:


> I hope you're right.


Also Musk mentioned that the cybertruck will have a charging capacity of up to 1MW using the v4 super/megacharger. That seems to indicate those will be added sooner than later.


----------



## bwilson4web (Mar 4, 2019)

garsh said:


> They'll be deployed for regional uses that are within the 500 mile range.


I would expect a 250 mi radius. Perhaps a little more if there is only a load one-way with an empty return.

Bob Wilson


----------



## Nom (Oct 30, 2018)

bwilson4web said:


> Some back of the envelope using:
> 
> 1.7 kWh/mi on the 500 mi test trip
> $135/kWh
> 7 mi/gal for $5/gallon diesel regular semi


1st Bullet x. 2nd bullet

= $227 / mi

3rd bullet works out to 5/7 = $0.71 / mi


Hmmmm


----------



## bwilson4web (Mar 4, 2019)

Nom said:


> 1st Bullet x. 2nd bullet
> 
> = $227 / mi
> 
> 3rd bullet works out to 5/7 = $0.71 / mi


At first I wondered why these calculations were made:

$227 / mi - the cost if the battery is thrown away on the first trip. Instead, we recharge the battery for the next trip.
~$0.50 / mi - the profit of driving EV, $0.20 / mi, over diesel, $0.71 / mi.
454 mi - the break even point for the battery. Thereafter, every mile earns $0.50 pure profit.
Bob Wilson


----------



## bwilson4web (Mar 4, 2019)

Another economic analysis of the Tesla semitrailer truck:





Bob Wilson


----------



## JasonF (Oct 26, 2018)

garsh said:


> It'll probably be 5-10 years before fleets start considering using these trucks for longer routes, and start requesting that Tesla establish v4's along the routes they use.


I'm fairly certain that the Semi (and its electric competition), plus the electric delivery vans from Rivian and Ford will be used exclusively in California to comply with its 2035 no more gas vehicles mandate. We probably won't see them anywhere else due to higher price and limited production until _after_ 2035.


----------



## francoisp (Sep 28, 2018)

JasonF said:


> I'm fairly certain that the Semi (and its electric competition), plus the electric delivery vans from Rivian and Ford will be used exclusively in California to comply with its 2035 no more gas vehicles mandate. We probably won't see them anywhere else due to higher price and limited production until _after_ 2035.


Based on Tesla's projected production volume of 50,000 semi trucks per year in 2024, and considering that demand for this type of truck in the US is around 200,000 per year, it's fair to say that we could see them around the country sooner than 2035. And what's to prevent these companies from moving their trucks outside California? The charging infrastructure? Well, considering that the cybertruck will have a one megawatt charging capability, the v4 chargers should be gradually appearing along the highways, a boost for the semi.


----------



## bwilson4web (Mar 4, 2019)

JasonF said:


> I'm fairly certain that the Semi (and its electric competition), plus the electric delivery vans from Rivian and Ford will be used exclusively in California to comply with its 2035 no more gas vehicles mandate. We probably won't see them anywhere else due to higher price and limited production until _after_ 2035.


Of course not because EVs are 1/3d the cost to operate and 1/100th the maintenance not counting tires. Yes, everyone else loves to pay 3x for their ICE vehicles instead of cheap to operate and maintain EVs.

Bob Wilson


----------



## JasonF (Oct 26, 2018)

bwilson4web said:


> Of course not because EVs are 1/3d the cost to operate and 1/100th the maintenance not counting tires. Yes, everyone else loves to pay 3x for their ICE vehicles instead of cheap to operate and maintain EVs.


For the most part though it won't be individuals buying electric semis, it will be businesses. And businesses tend to heavily departmentalize. Which means the asset purchasing department gets their cookie for spending as little money as possible on the semis, and if they cost more fuel and maintenance, that's another department's problem. Yes, that's horribly inefficient, but the way it works in big business, unless the CEO or board sends down an edict that they must purchase electric semis.

It's very likely Pepsi, the Tesla Semi's first customer, bought them mostly for the publicity of it - because now they're the "earth friendly" soft drink. The fact that they will save a lot of money on fuel and maintenance is important too, but the up-front cost could have only been by order of the CEO or board.

Also, there is an installed base issue. A lot of shipping businesses who might still be deciding whether to go electric already have a lot of semis driving around, and those can last up to a decade before they're retired. There is a slight advantage here where not a lot of them were purchasing new ones recently due to the pandemic and a driver shortage, but that's only 2 years out of 10. Take an average of what's left, and most won't start buying electric semis in any kind of numbers for 4-5 more years.


----------



## tivoboy (Mar 24, 2017)

JasonF said:


> I'm fairly certain that the Semi (and its electric competition), plus the electric delivery vans from Rivian and Ford will be used exclusively in California to comply with its 2035 no more gas vehicles mandate. We probably won't see them anywhere else due to higher price and limited production until _after_ 2035.


The CA 2035 gas vehicle NEW car SALES ban for Cars, SUVs and LIGHT DUTY Trucks as it indicates only applies to the vehicles up to light duty trucks. I’m not sure the delivery vans, urban delivery, Fedex type and certainly not Semi class - Class 8 commercial trucks applies. 

It’s important to note as well that this is only NEW vehicle sales so anything currently in the CA marketplace that is SOLD or USED already up to 12/31/2034 can be used and resold in the state without restriction. 

As well, vehicles of ANY type purchased OUTSIDE the state (or simply driven in) can be brought INTO the state and registered as CA DMV vehicles without restriction, which includes NEW vehicle sales from other states even after 1/1/2035.

But for now, we’re so far out into the future as technolgy goes it’s hard to tell yet really what various company or market forces are going to do.

update: I forgot to add that the 2035 CA ban also excludes plug in hybrids, although I think they can’t be more than 20% of car sales and they must be able to do 50 miles on their EV side alone

By 2035 I fully expect any PHEV in the marketplace to be able to do that many miles with its EV only side.


----------

