Will Tesla Roadster 2.0 Have New Advanced Battery?

APR 17 2018 BY GEORGE BOWER 56

The Unsolved Tesla Roadster Battery Mystery

In a previous article we described an engineering analysis of the Tesla Roadster.

Engineering Analysis: Tesla Roadster Specs Validated

In that article, we showed that the reason the Roadster has a 200 kWh battery was not to make range, but instead to make power … which the Roadster has copious quantities of … nearly 1 megawatt of power by the analysis in order to achieve 1.9-second 0-60 times and also hit 250 MPH. We also showed that the Roadster could be done using Tesla’s existing battery chemistry ….no new magic chemistry required.

Tesla RoadsterBut, something is still amiss in the analysis. Our model showed that the Roadster would have 764 miles of range with that 200 kWh battery. Tesla has told us the range is only 620 miles. What’s wrong with this picture? If you have designed a car that has 764 miles of range why would you tell people it only has 620 miles range? It makes no sense.

One could say the model is just wrong but you don’t need a computer model to convince yourself that the Roadster should have more than 620 miles range. A P100D with 200 kWh’s would go more than 620 miles and it’s a bigger car than the Roadster (We estimate the Roadster’s Cda at 20% less than the P100D). Plus, the model we developed matched P100D specs incredibly well. Not just 0-60 time but even quarter-mile time, as well as range, so we have faith that the model is correct.

There’s another problem with 200 kWh’s : cycle life miles.

With a battery twice the kWh’s of the P100D, the number of miles the Roadster battery would last would be twice that of the P100D using the same NCA battery chemistry and electrode design: Seems like over kill.

Then there’s the weight issue with 200 kWh’s. If you are fighting a weight problem, you certainly don’t want a battery any bigger than necessary, especially in a sports car.Tesla Roadster

So what’s the answer?

Here’s our speculation:

Tesla has a new battery in development that is waiting in the wings. This battery is capable of making 1 megawatt of power without having to be 200 kWh’s. It also would be capable of increased power during charging, so again no reason for 200 kWh’s.

The new battery could be:

– a modification to Tesla’s existing electrode design (thinner electrodes) designed for higher discharge and charging power. For a description of how this works see:

Argonne Computer Model and Implications for Model 3

– a different chemistry than NCA (or a low Cobalt version of NCA?). The push in battery tech right now seems to be low cobalt batteries since Cobalt is one of the more expensive ingredients of current batteries. Perhaps NMC 811?

What I am proposing is that Tesla is running the Roadster development using a parallel path approach. They have two possible candidates for the battery.

The first being existing NCA battery tech and the second being the next generation battery they have in development. When it’s time to go into production, if the new battery is ready, they can use that. If not, then they can using existing NCA tech. The new Roadster with existing NCA tech would not be as light as it would be with the new battery, but it still would be a viable product with unmatched performance specs (see previous article for performance specs).

What do you think? Is Tesla using a parallel path approach to Roadster’s battery design?

Are you in the “no new magic chemistry required” camp?

If you think Tesla has a new cell in development, what do you think that cell is?

Let us know in the comments section.

The model discussed in this article was a joint effort between the author and Keith Ritter.

Tesla Roadster 2.0 Prototype

Elon Musk with the new Tesla Roadster at the electric semi reveal event.
13 photos
New Tesla Roadster Tesla Roadster Tesla Roadster Tesla Roadster Tesla Roadster and Tesla Semi at the recent reveal event New Tesla Roadster

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56 Comments on "Will Tesla Roadster 2.0 Have New Advanced Battery?"

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Lamata

I said that from the very beginning on Reveal Day & no one believed me….Check my Blogs .. Cheers !

DEE

Ez! Model 3 has 310 mile range at 75KW, so x2 for 620 range with 150KW battery.. Factory wont even be finished yet with 2170 by the time Roadster2 comes out..

Benz

“Will Tesla Roadster 2.0 Have New Advanced Battery?”

They surely have something that they are developing and that is very promising. At the moment it’s just too soon to reveal anything about it.

The main reason for the reveal of the Tesla Roadster is “Hardcore Smackdown to ICE”.

The message is that it will not take too long before this will happen. They have the confidence that it will happen. And that they are very close to reach that point.

The reveal of the Tesla Roadster is their expression of confidence, and a warning to ICE car companies.

Lamata

YES ! … Very Nicely Said ! I couldn’t Agree more !

Apexerman

I think traditional car companies are well aware of electric technology and it’s evident by the billions of dollars being poured into development and production. They see the writing on the wall.

Mike

Yes, but like with the Model S when it first came out… I still don’t think they realize what EVs are capable of. In this case I am not talking about acceleration, but instead range and weight. If they do manage 620 miles with that acceleration they will have to do it without weighing twice what a Model S weighs today. Other ICE companies are shooting for Tesla’s current specs or to beat them by a little bit. Tesla just showed them that they need to think bigger.

Great deep dive on the new roadster, seems to make a lot of sense to do a new battery with the new limited sports car and it seems to line up timewise with the addition of the battery guru from Canada that they hired a couple years ago

ffbj

I think so. Maybe the new battery will go into the Roadster and the Semi.
It’s probably under development still and things could change before it goes into full production about the time the Semi and Roadster are ready.
I don’t think they would do a new battery just for the Roadster as it will be low production so that’s why I included the Semi too.

Just Speculation.

Hauer

Roadster 2 could be just 0.9 version of new battery.
Low volume, no big deal if the have to replace ALL of the batteries a few years down the road.
After problems are ironed out use this for S, X and the M3 Mk II.

Benz

They either do have the confidence that it’s good enough to use it in their EV’s, or they don’t have the confidence.

So, if they do have that confidence, then they should use it in ALL their EV models as soon as possible. Because it will make all those EV models better EV’s (because they will be equipped with a better battery pack than before).

Alonso Perez

That’s not how they roll with new technology. Volume always goes from low to high. Work out the issues, ramp up manufacturing, ramp down unit costs.
It’s a new chemistry for sure. No parallel path either. It’s far enough along that they know they will have it, but they will need to validate and refine for production and real world cnnditions

CDAVIS

From article: “Our model showed that the Roadster would have 764 miles of range with that 200 kWh battery. Tesla has told us the range is only 620 miles.”
——————–

Answer: The “620 miles” is “at highway speeds” per the Roadster reveal event when Elon stated “and that’s at highway speed”. So the EPA millage will likely be closer to the 764 model… which yes is nuts.

Regarding battery chemistry and cell size it will be same battery as used for Model 3.

Stan1

“which yes is nuts.”

It actually isn’t. They must top the fastest ICE around the hardest track, completely. The specs have to leave leeway for “smack down.” It’ll have to be something your teenager acknowledges basically destroys the previous specs. To do it correctly they really have to leave no reason to revisit the issue.

Stan1

Combined with Class 8 trucks and profitability, it takes a pretty strong measure of reality denial to not see where this ends up.

Stan1

I just realized, that Tesla has now made a promise (based on my suggestions of course).

Another Euro point of view

At least this new roadster is not vaporware. I mean for example not like the hundreds of preproduction cars which either are still currently tested (Porsche mission e & eTron quattro) or which test phase just finished (Jaguar iPace).

Get Real

Another Euro Troll POS once again points out how his Euro auto OEMs are just now starting to bring low volume production of products to market that might compete with Tesla’s current 2nd generation vehicles that have been in production for years now while Tesla is already started testing of 3rd generation vehicles.

Anyways, keep driving your “Clean Diesel” , you troll!

DJ

Somebody really needs to teach you some manners.

I’ll buy you a one way bus ticket to Compton or East LA for the day if you’re interested. Don’t think you’ll need the return trip…

Get Real

Speaking of serial anti-Tesla trolls.

Pushmi-Pullyu

“Somebody really needs to teach you some manners.”

What kind of “manners” is a troll like you gonna teach us? The finer points of picking your nose, or the best ways to upset readers and disrupt meaningful discussion of Tesla Inc. and its cars?

One Tesla basher supporting another. Just what InsideEVs does not need!

Mark.ca

So that’s were you learned your “manners”? Compton or East LA? That explains alot…

ffbj

That seemed like a pretty benign comment to evoke such effusive criticism.

pjwood1

Thanks for hitting on this question mark, George. Since reading a WSJ story, about 30% improved range from silicon’s increased use (possibly in NCA?), I thought maybe that could be where energy density comes from. Questions would be:

-If its NMC 811, how does the “cobalt cost per car” change?
-Would we be speculating for something similar to LiPo, where higher C-rates and charging come in exchange for higher weight per KWh?

It seems a law of physics, no “cake and eating”, when people talk battery selection. Better power flow properties (per KWh), with more weight, or better range with less KW (per KWh).

Of course, 200KWh roughly halves the needed C-rate, and doubles the mile loading when charging, but what makes the Roadster not very intimidating to ICE performance is weight. ~2,400 pound Mazda Miatas regularly school 4,000-5,000 pound beasts, at tracks. BEVs don’t have to get there, but they can’t afford to get much heavier.

(⌐■_■) Trollnonymous

Put that NMC 811 in a quad cab 4WD Pickup for me already!!!!!

Minus any AP crud though.

John

Have you actually driven with Autopilot?

54mpg

Which ever battery they use in the Roadster, they should Auction these cars rather than selling them for a fixed price.

Cars with even less specs are selling for much higher prices than the Roadster.

earl colby pottinger

That is why Elon said the roadster was a smack-down to ICE cars.

roddster

Sounds like a good application for a capacitor system?

Pat Free
For me they had a new battery techno in development for Roadster 2 since the beginning here as their Plan A. Fall back plan B with existing tech would make a very heavy and bulky Roadster. I never bought they could nicely do the perfs announced, in a nicely set Roadster form factor, with the current batteries available for Model S&X (18650 cells) or for Model 3 (2170 cells), because of the battery weight and likely the battery volume too, but also the charging times required. Key point missing here is at what rate it will charge, that is a lot more important than it seams and may add extra implications. On same day end of last year Tesla announced Roadster2, not mentionning anything special on charging, while 200kWh at current typical 120kW SuperCharger charging rate for Model S&X would require almost 2 hours which we all know is far too long to stop for such users, and the Tesla Truck new MegaCharger port that is a modular 4 x Very thick pairs of DC-only pins, likely capable to charge at up to 4 x 350kW = 1400kW combined +/-, and likely at 800 Volts or more. The Truck splitting… Read more »
Benz

“2 modules of 100kWh each”

That would be the optimal choise. If that would not have any negative side effects, of course.

Thanks for posting your comment.

Bill Howland

Maybe its fun to speculate, and of course, that is what engineers have to do all the time – predict the outcome of something yet to be designed.

But knowing scant about the motors or batteries or inverters throws enough uncertainty in the mix that about the only thing one could do to test this is to build a roadster out of an old junked Miata, and throw enough batteries in it to see what happens – presumably you’d want to use a large Tesla S type motor or maybe to get a more modern motor you’d wait around for a Model 3 that had plenty of cosmetic damage but the motor and gearbox still survived. And then see how many batteries you could shoehorn into the thing.

Doggydogworld

Roadster price, schedule and form factor all scream solid state. Plain old NCA won’t fit, otherwise they’d sell the car this year instead of 2021. And their margins would be crazy high at 250k.

Also, ‘smack down’ means a record time at Nurburgring, which isn’t happening in a 5000 lb brick.

It’s solid state or another next gen chemistry. ~$500/kWh in 2020. A few companies are selling very small quantities this year, Tesla will buy from one of those as they ramp. Or Panasonic will license the tech and build them.

Benz

Yes exactly, that was also my first thought.

No current technology battery cells.

Impossible, because of the weight.

Must be some new technology, that is currently still in development.

Pushmi-Pullyu
It’s almost a dead certainty that the 2020 Roadster will not use solid-state battery tech. Probably there will be some tweaking of battery chemistry between now and 2020, in 2170 cells or 18650 cells — likely the latter, since Tesla is still using those in the Model S/X battery pack, and the 2020 Roadster pre-production car appears to be using a double-stacked 100 kWh S/X pack. Year-on-year incremental improvements are expected, and there’s no reason to think that’s going to stop. But we have every reason to think that Tesla does not believe solid-state batteries will be ready for mass production in the near term; almost certainly not as soon as 2020. A relevant citation from August 2017: Some in the industry have been skeptical about the claim that [Toyota] could be… close to mass production of a multicell solid-state battery pack. Critics include Tesla CEO Elon Musk, who was asked about the development during Tesla’s quarterly financial results conference call earlier this month. Musk responded with exasperation about the possibility of a solid-state-battery breakthrough. “Tesla is the biggest buyer of lithium-ion batteries on earth,” he boasted. “You know who people come to first when they’ve got a lithium-ion battery?… Read more »
Doggydogworld

The Roadster will not be “mass produced”. Maybe they deliver two on 12/29/20 and a few per month thru mid-2021. That’s just normal Tesla calendar-ing. There will absolutely be solid state batteries in small volumes by then (NOT Toyota sized volumes).

Anyone talking about double stacked batteries needs to find a Roadster 1 (or Lotus Elise), put an 8″ foam block in the seat and try to fit under the roof. It’s absurd.

The prototype Roadster 2 did not have a 200 kWh pack. Probably 40 kWh of Toshiba SCiB or similar. Also, repeated 0-60 runs with a 3-4 minute cool down lap is not special. Tesla does that at every launch event.

Pushmi-Pullyu

I didn’t take a ride in Tesla’s new Roadster… and I suspect you didn’t, either. Here’s what someone who did so had to say about that:

“When I got in the vehicle for a test ride, the first thing I noticed was that you are sitting pretty flat like the original Roadster but significantly higher up off the ground. If I had to guess, I would imagine that Tesla has stacked two layers of 2070 cells between the axles.”

Of course, he meant 2170 cells. But if the new Roadster is using a double-stacked Model S/X 100 kWh pack, then that would be using the 18650 cells, not the new 2170 cells.

source:
https://electrek.co/2017/11/17/new-tesla-roadster-halo/

John

620 miles = 1000 kilometers. I think that’s all they cared about reaching, for the headlines.

Benz

I think that they should not have revealed the new Tesla Roadster yet.

At least they should not have revealed:
• 200 kWh
• 620 Miles range

Then we would not be discussing the new battery technology right now (2 years before start of production of the new Tesla Roadster).

Don’t show all your cards too soon.

Pushmi-Pullyu

I dunno, I think it’s entirely possible that Tesla (and/or Elon) wanted there to be lots of speculation that Tesla had developed some breakthrough new battery tech.

How does such speculation in any way hurt Tesla? Assuming they have no radical improvements planned in the near term — and I think that is the case — then encouraging people to speculate that they do, with articles like this one — analyses based on scant evidence which jump rather far to an unwarranted conclusion — is even better for keeping people talking and thinking about Tesla and its cars!

Pushmi-Pullyu
No. Not unless you consider two Model S/X 100 kWh packs stacked and welded together to be an “advanced battery”. See discussion on the Tesla Motors Club forum: https://teslamotorsclub.com/tmc/threads/200-kwh-roadster-pack-how-is-tesla-pulling-this-off.102274/ See, in particular, comment #25 and following comments in that discussion. * * * * * From the article: “…the model we developed matched P100D specs incredibly well. Not just 0-60 time but even quarter-mile time, as well as range, so we have faith that the model is correct.” There’s a pretty obvious fallacy there. Just because your computer model for the Model S/X P100D turned out to match the real-world performance quite well is no evidence that your computer model will work equally well for the “2020 Roadster”. It’s a very different design. * * * * * “What do you think? Is Tesla using a parallel path approach to Roadster’s battery design?” You seem to be ignoring the fact that Tesla has already given driving demos of its pre-production 2020 Roadster. Many people attending the Tesla Semi Truck reveal were able to take rides as the car accelerated up to speed, over and over and over, reportedly for about 45 minutes… without overheating. Whatever it is that allows the… Read more »
Smokey

Gorgeous looking car, But I’m waiting for the Model Y unveil…not because I want it, but because I want it out of the way. Cause the next unveil after that will be the Tesla pickup…I’m anxious to see what that looks like, if they make the front end all pointy for a low drag coefficient, they won’t need to worry about mass production, cause no one will want it. But I have my fingers crossed that Elon will do it right.

Sri

Perhaps 620 miles is just a conservative range with the expectation that the roadster will be driven hard

I seem to remember Elon saying something like, “and this is just the BASE Model!”, when refering to all the Specs!

mzs112000

They may be planning to have 620 mile range AND still have those high performance specs…
Again, they want to give a hardcore smackdown to ICE, they want it to handily beat ICE in every way…

The only thing that the chemistry will change is how much the battery weighs and how much space it takes up…

Chris O

Definitely not in the “no new magic chemistry required” camp because I just don’t see how a relatively small car like Roadster could fit twice the massive battery of a S/100.

koz

Tesla has a hybrid battery patent that mixes high power modules and high energy modules. The Roaster is the perfect application for it, although they should be able to achieve @500 mile pack. Lower weight, lower cost, less volume without sacrificing any meaningful range. Don’t know why they would go in the other direction as far as energy density. Doesn’t make sense.

PJW

Love the speculation, but —

Musk said, with a big slide, that the battery was 200kWh. So why would the premise of your article be that the battery ISN’T 200kWh??

Also, 620 miles was at HIGHWAY SPEEDS. Not EPA range as you’re appearing to calculate.

Doggydogworld

Model S 100D rating is 337 highway miles. Roadster is much smaller, should do well over twice that.

Pushmi-Pullyu

The higher power of the new Roadster’s powertrain will result in somewhat less energy efficiency (on a per-mile basis) than a Model S of similar size would have. I don’t know that this alone is enough to account for the discrepancy claimed in this article, but it certainly would be at least part of the reason.

Doggydogworld

Roadster cells are lower power than S P100D. Assuming 18650, that is. Specific power is lower in any event.

JP

“a different chemistry than NCA (or a low Cobalt version of NCA?). The push in battery tech right now seems to be low cobalt batteries since Cobalt is one of the more expensive ingredients of current batteries. Perhaps NMC 811?”

NCA is already a very low cobalt chemistry, less than 10% cobalt.

Doggydogworld

Tesla’s NCA has less cobalt than NMC 622 but more than 811.

Scott

I suspect the long range semi has four 200 KWh packs. They have been maximizing these packs for weight and power output for the semi. Then they thought, hey I wonder how well one of these packs would work in a sports car? They made the prototype and those are the numbers it put down. That’s why the roadster will be ready a little after the semi reaches the market.

Private

Current energy density of li-ion batterys is about 200wh/kg. Making 200kwh 1000kg. While not impossible, it whould make the car very heavy. This might help the accelaration. much downforce.

I dont think grafeen is ready yet. And metal-air batteries are still in lab settings only.

The lower range might be due to higher power. And ofcourse the added weight.