Tesla BEV Competition Developments

[OPRCE]

Your X% of cell power might work for electrochemical losses, but you need to use the square of current for resistive losses. Double the charge current (47 vs 94 per string) means 4x the heat per cell due to resistance, assuming the same resistance.

Thanks, also do you know if 5% for electrochemical losses would be a realistic figure (I just picked it arbitrarily as a total, in the absence of data on cell internal resistance)?

 

[mongo]

Thanks, also do you know if 5% for electrochemical losses would be a realistic figure?

No direct knowledge, sorry.
However, this paper seems to indicate it is mostly resistive (5% of total loss being modeling error or electrochemical) along with charger losses.
http://chrismi.sdsu.edu/publications/102.pdf

 

[wdolson]

Li-ion batteries have very low loss compared to other battery types, though I don't have the exact numbers. This is getting a bit behind the cutting edge of the latest chemistries, but it's a great resource for learning how batteries work:
Basic to Advanced Battery Information from Battery University

 

[Oil4AsphaultOnly]

1. Not sure I'm advocating it but saying it looks like that is what must be happening, otherwise at a loss to explain what packaging diff of up to 167.8kg goes into.


2. Leaf was passive air cooled, i.e. without even a fan it's the worst/cheapest design imaginable. This Audi pack is more like the Bolt EV, active liquid bottom-plate cooling, only [I presume] beefed up in all directions. Which would be no surprise if LG CHEM had an input on the design. AFAIK the Bolt EV battery has proved relatively reliable in all climate conditions and no problems since Dec.2016 with premature degradation, a stark contrast to the Leaf's sorry record.


3. Continuing comparison with Bolt EV pack, described by WikiPedia as a "stressed member":

Weight = 440kg for 60kWh with cells of 237Wh/kg = 253.2kg in cells leaves 186.8kg in packaging = 42.5%
which is almost identical to the percentage packaging in Audi pack, assuming cells have same GED.


4. Also of note from WP:
"The Bolt's battery uses "nickel-rich lithium-ion" chemistry, allowing the cells to run at higher temperatures than those in GM's previous electric vehicles, allowing a simpler and cheaper liquid cooling system for the 60 kWh (220 MJ) battery pack."

Have not found information on what those higher temperatures actually are, or how they compare to Tesla-typical ranges, but in general a higher delta between heat source and coolant should tend to increase the efficiency of the cooling system, right?

The simpler and cheaper system refers to the bottom plate as opposed to the stacked inter-cell cooling seen in the Volt:View attachment 376560
5. Audi e-Tron motors are rated for 300kW (peak) versus 150kW for Bolt EV, whereas the pack is less than twice the energy capacity, so it would appear the cooling system should be proportionately improved, or the chemistry improved to produce less heat output. I suppose the latter is less easy to achieve than the former.


6. Passive "tab cooling" inside the Audi modules could happen to some extent if e.g. thick aluminium cables conduct the heat out and there is then something else to wick it away, or the modules are filled in with an engineered cooling fluid which is electrically isolating but heat conductive, but it's most likely not part of this design as there has been no mention of it so far.
It may simply be a dual-function of the possibly quite thick aluminium module walls to act as intercalated passive heat conductors between the cell blocks to soak the heat down to the bottom plate.
From the schematic there is no indication of refrigerant running through the aluminium crash structure.


7. Something else that might help with cooling while charging is the battery configuration:

Bolt EV 288*208Wh cells, nominal 350V/3.65V = 96S3P at max charge 50kW = 143A /3 = 47.6A in each strand *3.65V = 174W
if 5% heating loss = 8.7W/cell, thus pack max heat load = 2.5kW

e-Tron 432*220Wh cells, nominal 396V/3.65V = 108S4P at max charge 150kW = 375A /4 = 93.75A in each strand = 342.2W
if 5% heating loss = 17.1W/cell, thus pack max heat load = 7.5kW

Here we see that the cell capacities are close [208 v 220Wh] but due to the electrical layout each cell charging at max produces waste heat (if assumption holds) at 8.7 v 17.1W, i.e. double for e-Tron, whereas the total pack heat load is tripled for e-Tron. Thus addition of 1 parallel path means the heat load per cell is more spread out, facilitating cooling.

[source for basic figures: Bolt EV, e-Tron]


8. Similarly for max discharge loads [if same 5% heating loss]:

Bolt EV pack supplies 150kW peak motor = 26.1W/cell, thus pack max heat load = 7.5kW

e-Tron pack supplies 300kW peak motor = 34.2W/cell, thus pack max heat load = 15kW

Conclusion: e-Tron pack has 1.58x capacity of Bolt but must eliminate triple the pack max heat load [which is double the cell max heat load] to avoid frying cells.


9. I'm not entirely sure any more what the original theory was! (apart from the frying batteries bit)

New info - e-tron uses only 83kwh of its 95kwh pack: Does Audi e-Tron Really Only Use 83 Out Of Its 95-kWh Battery Pack?

That means that charging to 80% is really just charging to 70% of the full pack capacity. That would explain the lack of charge taper.

 

[alloverx]

Article about EV Startups by John McElroy on wardsauto

 

[wdolson]

Article about EV Startups by John McElroy on wardsauto

John McElroy has a program on the YouTube. He's been pessimistic about Tesla's survival, but rather positive about the tech.

It is a good article and I pretty much agree. Tesla not only produces electric cars, but they have upped the automotive game in several areas. Most of the start ups and even main stream car maker offerings are competing with Tesla 5 or 6 years ago. There are only two EVs on the market with more than 300 mile range and both are from Tesla.

 

[CarlK]

John McElroy has a program on the YouTube. He's been pessimistic about Tesla's survival, but rather positive about the tech.

It is a good article and I pretty much agree. Tesla not only produces electric cars, but they have upped the automotive game in several areas. Most of the start ups and even main stream car maker offerings are competing with Tesla 5 or 6 years ago. There are only two EVs on the market with more than 300 mile range and both are from Tesla.

I don't see him being pessimistic about Tesla's survival. At least not in that linked article.

Looks he has learned a lot about Tesla from Sandy Munro. On the other hand what a moron that David guy from Bloomberg is. He seems to be clueless of the technolgy but that did not stop him from making all those smart ass negative comments.

 

[OPRCE]

New info - e-tron uses only 83kwh of its 95kwh pack: Does Audi e-Tron Really Only Use 83 Out Of Its 95-kWh Battery Pack?

That means that charging to 80% is really just charging to 70% of the full pack capacity. That would explain the lack of charge taper.

I had it worked out at 84.5kWh useful (11% buffer) from a video a month back and believe Audi now claim 12% = 83.6kWh

Anyhow, found this e-Tron charge curve (partial, on prototype vehicle) by Fastned Netherlands:

So there is an initially very steep 2-phase taper such that it charges at
~155kW at 70% (max)
~130kW at 80%
~85kW at 90%
~50kW at 100%

Which are certainly impressive numbers if carried over into the production version.

Meantime IONITY are up to 56 locations opened in Europe with 46 more currently under construction and have planning permission/contracts finished for another 268, aiming for a total of 400 by end of 2019.

 

[adiggs]

At those IONITY locations, is it 1 or 2 chargers per location, or are they Tesla Supercharger style, with 8-12 chargers per location?

 

[RobStark]

At those IONITY locations, is it 1 or 2 chargers per location, or are they Tesla Supercharger style, with 8-12 chargers per location?

From what I have seen they are between 4-8.

Tesla is between 2 in rural Montana to several 50 plus in China.

1 40 Supercharger at Kettleman City Ca and 1 42 Supercharger site in Oslo Norway.

 

[adiggs]

From what I have seen they are between 4-8.

Tesla is between 2 in rural Montana to several 50 plus in China.

1 40 Supercharger at Kettleman City Ca and 1 42 Supercharger site in Oslo Norway.

4-8 qualifies as a "real" charger location in my book. I realize there's lots of sites where 4-8 means long lines, but I've also been driving electric long enough to see chargers in the wild where 1 or 2 chargers at a location is the standard, with 0-2 of them actually operational.

So good on them!

 

[wdolson]

I don't see him being pessimistic about Tesla's survival. At least not in that linked article.

Looks he has learned a lot about Tesla from Sandy Munro. On the other hand what a moron that David guy from Bloomberg is. He seems to be clueless of the technolgy but that did not stop him from making all those smart ass negative comments.

I couldn't remember the name of the program. I haven't seen it in a while, but a year or so back they were speculating about which mainstream automaker was going to buy out Tesla. Nobody seemed to even consider the possibility that Tesla might survive as a stand alone company. Sandy Munro may have changed his mind. It may also be the two consecutive profitable quarters. A year ago Tesla was a company with a great car in the Model 3, but in production hell and Elon admits they were on the ropes there for a bit.

 

[Cobos]

1 40 Supercharger at Kettleman City Ca and 1 42 Supercharger site in Oslo Norway.

Actually they are about 1 hour drive on a 110km/h highway away from Oslo.
Nebbenes north of Oslo has 42 chargers ( and was Europe’s largest SC with 20 stalls, like 2 or 3 years ago).
Rygge south of Oslo was 30 and is in the process of upgrading to 44 or just finished upgrading to 44. I’ll probably use it in a few days on my way home and will see.

 

[Model 3]

Nebbenes north of Oslo has 42 chargers ( and was Europe’s largest SC with 20 stalls, like 2 or 3 years ago).
Rygge south of Oslo was 30 and is in the process of upgrading to 44 or just finished upgrading to 44. I’ll probably use it in a few days on my way home and will see.

According to this article Nebbenes is now Europe's largest again with 44 stalls, and Rygge is or will be #2 with 42.

Norge har nå Europas to største Supercharger-stasjoner

 

[Cobos]

According to this article Nebbenes is now Europe's largest again with 44 stalls, and Rygge is or will be #2 with 42.

Norge har nå Europas to største Supercharger-stasjoner

Darn did I get them mixed up? Yep a quick check at Tesla.com and it seems Rygge is the one with 42.

 

[OPRCE]

At those IONITY locations, is it 1 or 2 chargers per location, or are they Tesla Supercharger style, with 8-12 chargers per location?

IONITY claim they will achieve an average of 6 stalls per location, with each stall fed by 2 beefy rectifier-boxes rated at 175kW apiece = 350kW dedicated.

Have not as yet run across any >6 but have seen several locations in DE & CH with 4 stalls + 2 dummy pedestals prepared for easy expansion later ... see photos here.

Am eagerly awaiting release of CCS adapter, to discover what charge rate the S100D can really handle.
[M3 in Europe seems ATM software-limited to 120kW on IONITY.]

 

[neroden]

Or they could just choose option C and copy the successful stuff Tesla does and skip the rest. Listen, the point is that in a fully competitive market the terminal price for a product will approach it's costs.

Most markets are never fully competitive. The car market was a three-company oligopoly for decades. Barriers to entry are numerous.

 

[neroden]

Is there any way to invest in XPENG, it's privately owned correct?
@neroden

Privately owned, no way to invest in it AFAICT

 

[neroden]

We need to look seriously at the Chinese competition for Tesla.

Kandi is moving into the US; their cars are all short-range, though they're working their way into the long-range market; I think they're moving into the US because they're getting outcompeted in China.

When BAIC moves into the US market, it will be a big deal. And I think it will happen.

 

[OPRCE]

NextMove in Germany snagged a demo e-Tron and have just posted an interesting comparison:

Range challenge: Audi e-Tron vs Tesla Model X 90D vs I-Pace on Autobahn | consumption test

[Language = German, with English in CC]

Result at avg. 120km/h on motorway:

X 90D -- 24.8 kWh/100 km (39.9 kWh/100mi) = +23% efficiency over e-Tron

e-Tron -- 30.5 kWh/100 km (49.1 kWh/100mi)

i-Pace -- 31.3 kWh/100 km (50.4 kWh/100mi)

They also reckon e-Tron would be slower than X 90D over a 1,000km test due to lack of IONITY stations atm, but subject to change once availability improves.