EZZ

If they reach the target of 10% degradation in 30 years, it will change the world if it can be mass produced. Every home with solar will have one to maximize energy usage and cars will last forever...electric motors are vastly more reliable than ICE with minimal maintenance. I just hope somebody gets solid state going. 15 min charge with no degradation...really will win the transportation war.

sdls

It’s a wonder that Tesla was able to market an effective electric car with current technology. Solid state batteries are just next level.

EZZ

Well, the new 4680 design is tabless so you should be able to fully charge in about 15 min. Also, the battery will last much longer than current design so it could probably do 500k miles with less than 20% degradation. This battery is coming in the next 3 years. So at least we will be able to see incremental improvement in the next couple years before solid state comes online.

LeX2K

Correction: solid state batteries promise to be the next level. Making them cost effective, reliable and mass produced is a whole other challenge.

sdls

For sure, I watched the Battery Day presentation in full too

sdls

Well, of course. It took forever for lithium ion batteries to go from conception to the widespread use we see today. I think it’ll be a solid decade until we see solid state batteries reach any kind of technological maturity.

badboy86

Honestly....Im waiting..I really hope Lexus releases a EV version of the IS to compete with Tesla/etc...Im 3rd gen and want my next car to be EV...but don't want to leave IS or Lexus...but if i don't get a sporty luxury EV from Lexus...I'll be leaving them for good :-/

All4Lexus

This shows Tesla's biggest roadblock to Model 3/X/Y/S scalability was batteries. It put them through an unusual production hell cycle so that the supply chain can be properly be in sync to production volume needs (and satisfy TSLA investors). The shorts were counting on Tesla to fail in any form of battery production and collapse like a star going supernova.

Giga 1 laid down the plan for a Giga China and even further optimized factories that NO automaker can compete with in the scale up, buildout and go live cycles. Batteries are the greatest weaknesses in going full EV.

Toyota has no choice to stay in the efficient gas/hybrid realm until production ready options can be spun up in 5-10 years time. Petrol will still be around and if it can do 80% of what Tesla can do, then more power to Toyota to play their cards right with sales volume and profitability.

GM/Chevrolet/Ford could not play the 'volume' and 'profitability' path right -- old school car management got in the way. Who knows, Tesla's batteries might just be the global standard where Tesla car's get first dibs on the first 250k miles and everyone else can recycle and repurpose their batteries for the two or three more 250k lifecycles. That is a more environment friendly reuse situation which has the big car makers doing what they know best building vehicles and licensing the power source components.

We all will lose if each company needs their own battery solution. The economics are not there. Toyota gets it and is smart to have a very few full EV options. Honda also has learned from their accord plugin and clarity failures. Every company will decide whether to adapt on an evolutionary train over 15-20 years or adopt Tesla's bullet train and smartly go all in.

familyGX47

The Electric RAV4 was a joint development with Tesla when Toyota was one of the major investors and for compliance purposes. Since then, Toyota divested from Tesla as it doesn't meet its strategic objectives. Toyota corp is heavily invested in new battery technology. I actually interviewed with a company not too far from Tesla (Fremont, CA) that informed me that this small startup company was mainly started by Toyota capital investments and that Toyota is also investing in other new battery technologies, mainly solid-state, to strengthen its dominance in the auto market as the largest Auto company in the world with a second distant.

Toys4RJill

Weak hybrids? Doesn’t Toyota have a LS500h as well as RX450h. In Japan one can get the 5.0v8 hybrid model. Toyota dominates hybrid because they invested 25 years ago in it. They will do very well with EV in both fuel cell and battery as Toyota is a trusted, reputable brand.

wadeopgh

I have a 14 GS Fsport and a 14 GX both are great, BUT currently in our garage is a 19-tesla model 3. The Tesla I'm watching belongs to a friend while he is out of the country for a couple of months. I can honestly say that it is AMAZING, everything from the Acceleration, UI design and interior design is very well executed.
I have been thinking about selling the GS and picking up a model Y, the car is that much fun to drive. If you are not sold on the looks just drive one and you will never look back. This coming from a die-hard Lexus / Toyota fan. Now with that said the Rav4 prime looks to be on my list to test drive...

I wish they would just release a EV as that is what the people want, Tesla on the other hand is a good 10 year ahead of all other automakers, there will be no way for them to compete on price once they are releasing the new autos with cheaper batteries(they are getting cheaper all the time for them). The legacy automakers will have a very tough time competing if at all.

Toys4RJill

I agree... But other cars can be exciting, amazing and inspiring as well. I often read on here that some say that Tesla's are not luxurious, I somewhat disagree that are not but I am not quite sure that a Tesla is worth the price based on interior compared to other luxury brands....but the performance is there...I just looked up the performance model for the 3 in CAN dollars, $75K gets you 3.4 secs and 481km of range...and for $20K less, you get 402km of range and 5.6sec..

EZZ

Good article on comparing the next generation 4680 pack vs. the Model 3 2170 pack which is currently the best on the market. The 4680 in theory should be able to charge from 10% to 80% in 15min which will definitely be game changing for a lot of folks on the fence. It can output more power too which means the Tesla cars are definitely going to get much faster in the future

Tesla Model 3 With 4680 Pack: Estimated Charging Time, Power, And Size

[img]data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAJCAYAAAA7KqwyAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAABpJREFUeNpi/P//PwMlgImBQjBqwLAwACDAAOVfAw9/ZDvcAAAAAElFTkSuQmCC[/img]
Oct 14, 2020 5h ago
24

By: George Bower

It appears charging times could be competitive with gas cars.

Tesla’s Battery Day presentation outlined big improvements in cost, energy, charging time, and pack size. We will show you our estimate of the new charging profile, an overlay of 2170 vs 4680 pack size, and an estimated cross-section of the new 4680 pack. We’ve also estimated the series-parallel cell configuration and a potential way Tesla will electrically connect the cells.

In a previous article (ref), we outlined the results of a preliminary thermal analysis that suggested that Tesla’s new 4680 pack would use a much simpler and easier to assemble flat plate cooling scheme and ditch the cooling snake in between the cells that they have been using since day one.

While Tesla didn’t specifically say it will go with flat plate cooling, it is strongly suggested for a number of reasons. The primary one being that you can’t effectively cool these larger diameter cells through the sides. The most effective way to cool the new tabless design is through the ends of the cells since the new tabless design provides a great thermal path between the cell cap and the inside of the cell.

The copper anode electrode plates themselves act as great cooling fins and provide nice uniform temperature distribution within the cell. The other reason we think flat plate cooling is likely is that Elon Musk said that the cells are glued to the bottom and top sheets of the pack. While his quote is in reference to added shear strength in the pack, we think the top and bottom sheets will also double as cooling plates. In the Model 3 pack, the cells are glued to the cooling snake.

Our analysis makes a direct comparison between the Model 3/Y 2170 pack and a theoretical 4680 pack. You may ask why we chose the Model 3 pack to make the comparison when Tesla has stated that the 4680 pack is primarily aimed at the Semi and Cybertruck and Model S Plaid. The reason we chose to make the comparison with the Model 3 pack is that we know a lot about the Model 3 pack, so it’s much easier to quantify the improvements against a known baseline than an unknown baseline in the case of the Semi and Cybertruck.

Summary

At 85 deg F ambient, calculated charging time from 10% to 80% with the 4680 pack was reduced from 25 minutes to 15 minutes. If you only need a 50% charge, you can be done in 7 minutes. That’s almost as fast as gas.

The estimated maximum charging rate increased from 250 kW with 2170 pack to 275 kW with the 4680 pack. The 275 kW charging rate holds constant from 10% to 50% state of charge where we begin to taper the charging rate. We begin to taper when the cells reach their temperature limit assumed to be 45 degrees C (113 degrees F) based on Model X data. The taper point is a function of ambient temperature since the A/C system’s performance decreases at higher ambient temperatures. The charging profile comparison is shown in figure 1 vs time and vs state of charge (SOC) in figure 2.
[img]Above: A comparison between the 2170 pack charging profile and the estimated 4680 pack (time-based), credit Keith Ritter PE Engineered Compliance.
[img]Above: A comparison between the 2170 pack charging profile and the estimated 4680 pack (SOC based), credit Keith Ritter PE Engineered Compliance.

We see a significant reduction in the size of the pack

Eliminating the cooling snake allows Tesla to pack the cells closer together. This is a plus because it reduces the polar moment of inertia and improves vehicle handling since the mass is concentrated more towards the center of the vehicle.
[img]Above: 96S9P 76 kWh 4680 pack Credit Keith Ritter PE Engineered Compliance
[img]Above: Overlay of the estimated 76 kWh 4680 pack on top of the 2170 Model 3 pack, Credit Keith Ritter PE, Engineered Compliance

Cross section of our estimated 4680 pack shows top and bottom flat plate cooling and cell electrical connections

We see a much simpler way of making the electrical connections in our estimated 4680 pack. We think Tesla will eliminate the "finger collector" concept with wire-welds etc. and go to a simple plate-based collector that can be directly welded to either the "tabless" anode or the cathode-connected can. To connect the + of one group to the - of the other, they go back to their Model S-based "Inverting" technique where they flip the cells of every other parallel cell group.
[img]Above: Cross-section of estimated 4680 pack credit Keith Ritter PE Engineered Compliance

As previously stated, we estimate both a top cooling plate and a bottom cooling plate with the cell glued to the plate. The cooling plates would also provide shear strength to the pack. We estimate a 30%/70% split in heat transfer between the cathode (aluminum) end of the cell and the anode (copper) end of the cell.

Could Tesla get by with just a bottom plate? We think not. This issue is discussed in further depth in the detailed discussion below.

Detailed discussion

Our thermal electrical model includes all the specifics of the pack. Dimensions, cell dimension, amp-hour ratings, thermal conductivities, etc. One key ingredient is the resistance of the cell since this determines the cell heat generation (I squared R losses). Sean Mitchell did an excellent interview of Ravi Kempaiah wherein Ravi explained the resistance reduction for the new 4680 tabless cells. The presentation is linked above and the resistance discussion is at 8:11 in the video. Based on his presentation we used the 4680 initial internal resistance = 3 mOhms @ 10% SOC and tapering to 2 mOhms at 80% SOC. The 2170 cell was 23/20/20 mOhms. So we reduced the cell resistance by a factor of 10. This compares to a 5-20 times reduction that Tesla quoted in its patent app.

In addition, the refrigeration capacity is an input to the model. We chose to stick with the existing Model 3 refrigeration capacity of 2-3 tons (depending on ambient temperature). However, it is possible Tesla might increase its stack chiller and AC compressor sizes to provide better pack cooling.

The thermal mass of the pack also comes into play. During the first part of the charge at the maximum charge rate, the cell generates more heat than the refrigeration system can keep up with, so the pack begins to heat up. The thermal mass delays the onset of cell overtemperature as it stores the heat. When the cells reach their temperature limit (45C=113 F), we begin to taper the charge rate.

Figure 6 gives you an idea of how the heat rejection of the pack and the heat removal capability of the A/C system compare. Note the decreased A/C performance at higher ambient temperatures. This is why the initial taper point off of max charging power occurs at a lower SOC at higher ambient temperatures.
[img]Above: A/C performance vs ambient temperature, credit Keith Ritter PE

Can Tesla get by with only a bottom cooling plate?

It would be simpler and lower cost to have only a bottom plate. Most (70%) of the heat goes out the copper (anode) ends of the cell. Why not orient all the parallel cell groups anode end down and just use a bottom plate?
More On Tesla's 4680 Battery Cells:[img] Tesla 4680 Cell: Thermal Analysis Suggests Unique Cooling System Design

[img] Tesla's New 4680 Tabless Cell Design Adds Energy, Range, & PowerThe patent is pretty clear that only the copper current collector will get the "tabless" end treatment. The aluminum collector still only has a single tab at the middle-end of the jelly roll that connects to the can. It likely just gets too complicated to do crazy interleafing of segmented tabs at both ends at the same time.

The heat transfer calculations say the bottom-cooling-to-copper-only configuration could only do 70% of what top/bottom plates can do and would create a larger axial heat gradient. The negative tab terminal end will be the hot spot. If we put a second plate on, that provides cooling to the - tab can end, we shift the hot spot about 1/3 the way down axially and can extract 30% more heat at the same "hot spot" cell peak temperature.

Two plates mean less cell thermal stress/deterioration and better cell life. Tesla will be gluing in these cells for life: The million-mile-battery. If it will also be ramping up charging kW some more to stay "leading edge," it HAS to do everything to ensure minimal thermal stress/degradation on these cells. A second cooling plate is cheap insurance. We think flipping the cells with every cell group also helps cell-to-cell conduction to spread-out the heat in the cells' axial and reduce thermal gradients between "top" and "bottom."

Sandy Munro, in one of his interview videos, also predicts there will be both top and bottom plates. He's been spot-on about his forecasts for Tesla's battery and structural changes so far.

Motorola

Clearly what people clearly want is a hydrogen GS sold exclusively in California.

Toys4RJill

The new Toyota Mirai is an EV.