Tesla 4680 battery

[JeffKeryk]

@Cujet , @OVERKILL and others please chime in...
This article claims:
"The 46 millimeters wide, 80-millimeter long battery cell will increase energy density by five times, increase range by sixteen percent, and improve power output by six times."

What does this mean in layman's terms? "Increase range" sounds self-explanatory and good, regardless. "Improve power output" means what to a Model 3 owner, like me?
Perhaps best of all, the article suggests advancements in battery tech like this gets EVs closer in price parity with ICE vehicles.
Your thoughts? Thanks in advance.

I am considering another Tesla is perhaps a year if and when EV technology takes a decent step forward over our 2018 Mid Range. By the way, the Kato Road facility is near the Fremont factory and the new battery factory is just east of Fremont in Lathrop, CA (hot Central Valley).

Tesla 4680

 

[UncleDave]

@Cujet , @OVERKILL and others please chime in...
This article claims:
"The 46 millimeters wide, 80-millimeter long battery cell will increase energy density by five times, increase range by sixteen percent, and improve power output by six times."

What does this mean in layman's terms? "Increase range" sounds self-explanatory and good, regardless. "Improve power output" means what to a Model 3 owner, like me?
Perhaps best of all, the article suggests advancements in battery tech like this gets EVs closer in price parity with ICE vehicles.
Your thoughts? Thanks in advance.

I am considering another Tesla is perhaps a year if and when EV technology takes a decent step forward over our 2018 Mid Range. By the way, the Kato Road facility is near the Fremont factory and the new battery factory is just east of Fremont in Lathrop, CA (hot Central Valley).

Tesla 4680

Improved power output by 6 is likely the sustainable output prior to electronic cutback due to thermal protection .

This also means that the unit will sustain high amp charging longer before being throttled (faster road trip time)

This aids both higher max re-gen and full throttle output longer (aid performance)

I suspect the higher output really aids the semi and the up coming cyber that need to tow.

This will be one step closer to parity with liquid fuel, and a nice bump that will keep teslas door to door time faster than everyone and be able to offer higher performance.

 

[OVERKILL]

@Cujet , @OVERKILL and others please chime in...
This article claims:
"The 46 millimeters wide, 80-millimeter long battery cell will increase energy density by five times, increase range by sixteen percent, and improve power output by six times."

Dave covered the improved power output (which also means power input) quite well.

Increased energy density is likely density of the packs themselves. Improved packaging and cell design means that they will be able to pack more capacity into the same space. Say for example, a traditional 85kWh pack is comprised of 200 "packs", that means that each pack is 375Wh. Increasing that density 5-fold with these new cells means that each of those packs can now be 1,875Wh; 1.875kWh. So, you only need 40 of them to make your 75kWh pack. This means that within the space you previously used for 75kWh, you can now pack 375kWh of storage.

The increased range is likely due to better charge/discharge characteristics. The ability to draw the cell down further and charge it up higher without damaging it.

No mention of the cell chemistry in the link, is this traditional Lithium Ion or is this Lithium Iron Phosphate?

 

[E365]

I found this video helpful in explaining the benefits and “numbers” of the 4680 cells.



Also came to post this. Since the 4680 pack will be structural, the unibody will apparently have no floor. Therefore the seats will essentially be bolted to the top of the battery pack.

From someone in the Berlin plant who talked with engineers in person and took photos. More info deeper in the Twitter thread.

 

[Cujet]

The 4680 seems to be a brilliant piece of engineering. That's because it's a TOLERANT high drain/high charge design that can be actively and effectively cooled (by nature of it's design/construction). As mentioned in the posts above, faster charge and discharge! But we really need to be careful about "energy density", and the CLUE is in the modest increased range specs. There is no magic here. At it's core, it's just a lithium battery.

The battery has about 5x the power because it is 5x bigger/heavier. What this means is that we simply use fewer cells for the same capacity. The battery also has a so called "dry" electrolyte, which should solve some operational problems, such as eliminating damage during cold charging.

The ROUGH math goes like this: 2170 is 21mm x 70 mm = 96,931 cu mm. The 4680 is 46mm x 80 mm = 531,539 cu mm. 531,539/96931=5.48 so the 4680 is 5.48 times the volume of a 2170


The analogy using "Duracell's" is this. Your bat pack can contain 1000 AA cells, or 400 C cells or 200 D cells. All do the same job, have the same basic chemistry and will push your car the same distance.

Will cars that have 4680's have more range by virtue of the battery itself? Not much. The geometry of large cylinders takes up space.


However, the expectation is that under most conditions a 5 minute charge will get some real miles. And a 15 min charge gets it all.

 

[JHZR2]

The crushed end jelly roll is superior to a tabbed design (small tabs inserted in the jelly roll, with limited cross sectional area) for operation at rate, because there is a lot more conductive area to carry the current. The cells can be designed with lower impedance, which results in easier access to power, and more accessible energy. Fewer busbars, voltage leads, BMS boards, etc. all come into play for the larger cells. That is an advantage in manufacturing and use. Fewer parallel cells also means less likelihood that a bad chill bring down a cell group, or irregularly share current during high rate operation.

The downside to the larger cell is thst conduction pathways for getting heat out are much longer. The inside of the jelly roll can be significantly hotter than the inside, and it is harder to get any of that heat out the cell walls, where the surface area is. So it becomes more important to get impedance down, since heat is generated at the square of current but just directly to resistance (I^2 R). Thus there is a much greater reliance on getting heat out through the bussing..

 

[JHZR2]

I found this video helpful in explaining the benefits and “numbers” of the 4680 cells.



Also came to post this. Since the 4680 pack will be structural, the unibody will apparently have no floor. Therefore the seats will essentially be bolted to the top of the battery pack.

From someone in the Berlin plant who talked with engineers in person and took photos. More info deeper in the Twitter thread.

That is interesting. Vents for the cells will be vertical, and when the cells release, that’s awful close to the person. I’m not a fan, and have to wonder the level of abus Ive testing they performed on this design. Sometimes plausible deniability is key, and it isn’t done.

 

[UncleDave]

The 4680 seems to be a brilliant piece of engineering. That's because it's a TOLERANT high drain/high charge design that can be actively and effectively cooled (by nature of it's design/construction). As mentioned in the posts above, faster charge and discharge! But we really need to be careful about "energy density", and the CLUE is in the modest increased range specs. There is no magic here. At it's core, it's just a lithium battery.

The battery has about 5x the power because it is 5x bigger/heavier. What this means is that we simply use fewer cells for the same capacity. The battery also has a so called "dry" electrolyte, which should solve some operational problems, such as eliminating damage during cold charging.

The ROUGH math goes like this: 2170 is 21mm x 70 mm = 96,931 cu mm. The 4680 is 46mm x 80 mm = 531,539 cu mm. 531,539/96931=5.48 so the 4680 is 5.48 times the volume of a 2170


The analogy using "Duracell's" is this. Your bat pack can contain 1000 AA cells, or 400 C cells or 200 D cells. All do the same job, have the same basic chemistry and will push your car the same distance.

Will cars that have 4680's have more range by virtue of the battery itself? Not much. The geometry of large cylinders takes up space.


However, the expectation is that under most conditions a 5 minute charge will get some real miles. And a 15 min charge gets it all.

I dont see the range from a 5 minute charge from 5% changing much - unless tesla ups the volts, or amps from 250 today

On the 15 minute yeah - pretty close to full, I think well see the 15 minute charge take us from 5-90 vs about 30 minutes today as we "should" see the full 250K for much longer,

Since today you only get the 250KV from a really low SOC Id imagine you can bring full charge voltage to the party at around 50% or so, with this pack so interim stops with fuller packs will be more productive.

The cars could also theoretically take the higher voltages supplied by the EA network, but thats a wish.

It will be interesting to see.

 

[DwightFrye]

Tesla is so far ahead of everyone else regarding battery technology that I predict that if they can produce enough to meet the demand, they will either be selling batteries to other automakers, or licensing their technology to an independent battery manufacturer who will then be supplying other automakers.

 

[IcarusLSC]

'D' cells are back!

 

[OVERKILL]

The 4680 seems to be a brilliant piece of engineering. That's because it's a TOLERANT high drain/high charge design that can be actively and effectively cooled (by nature of it's design/construction). As mentioned in the posts above, faster charge and discharge! But we really need to be careful about "energy density", and the CLUE is in the modest increased range specs. There is no magic here. At it's core, it's just a lithium battery.

The battery has about 5x the power because it is 5x bigger/heavier. What this means is that we simply use fewer cells for the same capacity. The battery also has a so called "dry" electrolyte, which should solve some operational problems, such as eliminating damage during cold charging.

The ROUGH math goes like this: 2170 is 21mm x 70 mm = 96,931 cu mm. The 4680 is 46mm x 80 mm = 531,539 cu mm. 531,539/96931=5.48 so the 4680 is 5.48 times the volume of a 2170


The analogy using "Duracell's" is this. Your bat pack can contain 1000 AA cells, or 400 C cells or 200 D cells. All do the same job, have the same basic chemistry and will push your car the same distance.

Will cars that have 4680's have more range by virtue of the battery itself? Not much. The geometry of large cylinders takes up space.


However, the expectation is that under most conditions a 5 minute charge will get some real miles. And a 15 min charge gets it all.

Yes, that's misleading for sure, as the convention for using energy density is that it's proportionate to the space occupied. If I'm comparing a nuke to solar, the nuke is insanely more energy dense. Solar doesn't gain a huge increase in energy density just because we make one big panel instead of using smaller panels fitted together in the same area. I had assumed that they had improved capacity for a given size (module/pack) and that the range claim was separate and was again being referenced from a specific kWh perspective, so like a 75kWh pack using previous cells vs a 75kWh pack using the improved cells, range increased by 16% due to the ability to utilize more of the battery's capability; less of a safety margin in charge/discharge because of improved cell design and chemistry.

If they have actually NOT improved density and it is as you describe, then this is much less impressive than it appears. The big cells will be more difficult to package, so in fact you'll be occupying more space for the same kWh capacity. @JHZR2 brought up some excellent points on the thermal side of things as well.

 

[loneryder]

With the battery as the platform, what happens when the battery dies or has problems? Also occupants sitting on a battery like that?? Doesn't sound great to me. What about the danger of fires?

 

[JeffKeryk]

With the battery as the platform, what happens when the battery dies or has problems? Also occupants sitting on a battery like that?? Doesn't sound great to me. What about the danger of fires?

IMO, the way the car is engineered and built is the critical component.

 

[sk_pete]

With the battery as the platform, what happens when the battery dies or has problems? Also occupants sitting on a battery like that?? Doesn't sound great to me. What about the danger of fires?

hahaha, roasty-toasty when this catches on fire!
bacon & eggs !

 

[Cujet]

I dont see the range from a 5 minute charge from 5% changing much - unless tesla ups the volts, or amps from 250 today

That's exactly correct. However, Tesla is already upgrading to 300Kw (and is talking about 350), AND the 4680 can easily take the full amount across most of it's charge state, that means that the 300Kw 1/10th hour battery charge will be about 30Kwh. The megacharger (one megawatt) is coming too, and we think that's specifically for trucking, which are likely to use the 4680's.

Possibly of interest is Musk's dismissal of other manufacturers 350Kw plans as "a children's toy". While 350Kw is off in the future for most manufacturers, it's pretty clear "fast charging" is in the works everywhere.

 

[Cujet]

brought up some excellent points on the thermal side of things as well.

Well, that's the brilliance behind the 4680. It's designed and packaged to adequately deal with the thermal issues. First by being tabless, reducing internal resistance, and therefore heat. Second by it's designed in ability to transfer heat through the top and bottom, instead of the sides. Tesla is well aware of the larger roll reducing heat transfer through the sides.

The conduction of heat through the sides has always been problematic, as it must travel from the center of the cell, through a number of insulators and out into the case. Not so with the 4680.

 

[JeffKeryk]

Please allow me one more stupid layman question...
For sake of conversation, let's say the 4680 is a level better, all things included.
Can another company simply cut one up and copy it, sorta like BITOG does with a Fram XG7317?

By the way, I learn from youz guyz all the time. Appreciate you.

 

[PandaBear]

It means in layman's term packaging can be wasteful and is a low hanging fruit to address. Tesla start with 18650 because it is easy to build with economy of scale already there, then gradually grow the cell size to their production and investment, and now they are at 4680 because it is justified. Maybe further down the road they will move to prismatic and pouch cells because it is even more cost effective and efficient.

It takes volume to justify investment and it takes investment to justify development, and with those comes cost reduction and bigger volume.

 

[UncleDave]

Please allow me one more stupid layman question...
For sake of conversation, let's say the 4680 is a level better, all things included.
Can another company simply cut one up and copy it, sorta like BITOG does with a Fram XG7317?

By the way, I learn from youz guyz all the time. Appreciate you.

Sure, it can be copied, but unless you are investing in the manufacturing plants and techniques employed in building it and the associated packs in mass at speed there is no point.

Finding a way to make it quickly and affordable is as critical or more the the battery design itself.

The battery day footage talks about the dry film technique acquired from maxwell tech.

 

[UncleDave]

Sandy came really close to guessing what the dimensions of the 4680 were.

He talked about the battery casing between the 2 batteries resulting in less weight and remarked one wouldn't necessarily think that initially, as well as volumetric efficiency for the space.