Published on May 17, 2019 |
by Guest Contributor
17. May 2019 by Guest Contributor
The article was written by Simon Barke and Myles Clark. They each have a PhD in physics, work for an international space mission at the University of Florida and understand scientific data quite well.
Matthew Mostafaei, Audi chief of e-throne, presented data taken from Twitter during the New York Auto Show without source source. (It's plagiarism.) The data was misrepresented by plotting it on another axis. (It's a fake.) He used the data to show the e-throne's charge superiority over model 3, when it actually shows the opposite. (It's deception.) You can call this good marketing. I call it a brazen lie. At best, it is a very misleading accident.
A chart presented by Audi's head of e-faith and connected cars in the US, Matthew Mostafaei, made the rounds this week. During a New York International Auto Show presentation, he pointed out how much longer Audi's new all-electric "e-tron" SUV can maintain a 150 kW charging current. The point in the chart: In many situations, the e-throne is charged more quickly by a 150 kW charger than a Tesla on the upcoming 250 kW "Supercharger V3." And the faster you take, the faster you come. Right? No, not quite …
There is a lot of confusion about electric vehicles. Different test cycles, range, charging status, efficiency, charging current and charging current. This lack of general knowledge helps companies make unjustified demands on their cars.
I came by phone with Mark Dahncke (director, Product / Technology / Motorsports Communications of Audi USA) about this. He confirmed the source of the data and admitted that Audi never contacted or credited the original author. He further regrets that Audi (accidentally) forged the underlying data. Even though he now denied that the chart presented meant that the e-throne could load faster, he still defended Audi's basic claim that a high charge force helps you reach the destination faster. Oversimplified statements like these are not just targeted misleading. They also add general EV confusion, which is bad for everyone.
Let's set the record, try to understand what Audi did, and find out what the data really shows. Below is the slide Audi showed during the New York Auto Show presentation. The diagram shows the charging current (20 to 250 kW) of various electric vehicles over the battery charge (0 to 100%). The first indication that something is very fished here is that unspecified Tesla at a third generation Supercharger starts charging at 1%. (The black line and the red arrow / text were added by me.)
Audi got the data from Twitter – and didn't know how to read it.
When I confronted Audi with the charges of plagiarism, I was told that they used an image published by Electrek. But Electrek is not the author of the data and instead called the original Twitter source. It was published 2 months ago by the user "@privater" on Twitter ("u / privaterbok" on Reddit).
I made a comparison map of supercharger v2 va v3 based on test firmware of 2019.7.11 @marc_benton @Teslatunity @ Model3Owners
It feels surreal charge 15-80% within 24min. Thanks @elonmusk @ Tesla for the update, you make my car awesome again. pic.twitter.com/3TZSpChhiK
– private (@privater) March 7, 2019
On reddit here.
Audi's mysterious charging profile is a perfect match. What is striking, however, is that the data that was posted on Twitter was plotted on a non-equivalent horizontal axis. Note that 28%, 30%, 40%, and 44% are spaced at the same distance on the chart while being different by 2%, 10%, and 4%, respectively. Audi blatantly ignored it, copied and pasted the v3 slot on its traditional, equilateral axis, and stretched it arbitrarily so that it somehow worked with the rest of the Audi's chart. The company never cared about controlling the underlying data. No wonder they were confused to the point that their version now starts with the car in a negative charge state!
Fortunately, U / Private Book used Reddit to upload the original data to a spreadsheet. I managed to create a corrected version of the Audi & # 39; s chart that also includes a new charging profile for the upgraded 150 kW Tesla Supercharger V2.
It is important to note that the 250 kW Supercharger system is still in a test phase and further improvements are likely. Both Tesla charging profiles do not include automatic preheating of the battery, which will increase the charging power at low charging status. So, the Tesla charger profiles shown here can be seen as conservative. Anyway, now that we have corrected data to work with, we can answer the question of what this data actually tells us.
In its present form, it is purposefully misleading. Don't take me wrong – it's very impressive that the e-tron can maintain a higher charging power at higher battery charge status. But does this help you get anywhere faster? Not without range and efficiency to back it up will not …
Charging power is not charging speed!
First and foremost, we must adjust the horizontal axis. Who cares about battery percentage? The important information for the driver is how far they can go before they need to fill up. The battery of a low-powered vehicle does not get me anywhere, whether fully charged or not. For Audi, a 100% charge corresponds to 204 miles (EPA test cycle). The Tesla data Audi copied from Twitter was measured from a Model 3 Long Range, so I would correctly spend 325 miles for a 100% charging status. In the diagram above, the 40-kilometer and 200-kilometer range equivalents for e-tron and Tesla are highlighted so that we can rescale the tracks accordingly and plot the charging power over the electric vehicle area.
This version of the chart is a little less misleading, but we still have a new step before this is a real apple-to-apple comparison. That step is to take into account how fast the vehicles actually load into devices that are more relevant to the real world. For that, we need to adjust the vertical axis to reflect the charge rate (charge rate in miles per hour). This calculation depends not only on the charging power but also on the vehicle's efficiency. The more efficient a vehicle is, the more area you add for any charging power.
Model 3 Long Range maximizes at a ridiculous 1000 miles per hour at 250 kW of charging power. This translates to close to 600 miles per hour at the 150 kW level. If you do the math, these values include an approximately 8% loss (mainly due to heat). If we assume the same loss of 8% to charge the e-throne, the picture looks very different. Audi's entry into the electric vehicle market is peaking at just over 300 miles of reach per hour on the charger because of its inferior efficiency: it needs to charge a much larger battery that provides significantly less range than model 3's much smaller battery . 
Finally, we can directly compare the speed at which the two cars can charge. The area under the charging profile is directly related to the time it takes to add a drivable area to the car. As an example, I chose a realistic remaining area of 40 miles before we start charging. We charge both cars to 200 miles (since Audi can't get beyond 204 miles). You can see in the diagram above in the highlighted range between 40 and 200 miles: The larger this area, the faster the charging process will be to add 160 miles of range. So in reality, the Audi e-throne takes far slower than the Tesla Model 3, even at the older generation of Supercharger.
How long does it take to add 160 miles of reach?
@privater, the Twitter user who published the original data, has also posted range charts vs. time while they are charging.
Here is v2 vs v3 SoC vs time pic.twitter.com/idfDpOWtMe
– privates (@privater) March 7, 2019
From these maps we know for sure that It took 15 minutes to charge from 40 to 200 miles on the third generation Supercharger. This would translate to about 21 minutes when charging the same car on a V2 Supercharger. And the e-throne? Well, if our cost interest estimates are correct, it will take 36 minutes for the e-faith to add 160 miles of reach.
Can this be true? Appears, our estimate is spot on. User "Elbil24" published a video on YouTube that lets the e-throne from 1% to 99% at a 175 kW fast charger. For this charge session, it took exactly 36.7 minutes to charge from 20% to 98% (which corresponds to 160 miles on the EPA test cycle).
So let's go back to Audi's headline: "Quick to charge = quick to arrive." This is true, but Audi forgot to mention that the real charge of e-faith is discouraged slowly.
Here's what to take away from This article: Don't trust anything published by the Volkswagen group. After all the coverups of the past few years, it is not surprising that Audi continues to deceive the public with falsified data and distorted arguments. Some companies never learn. I just hope the customers will finally.