Stop the Press! Tesla announces REAL HP numbers for P85D and P90L

[bonnie]

Don't you all have day jobs?

 

[Auzie]

Don't you all have day jobs?

It is Saturday!!!

 

[SW2Fiddler]

Another round of beers please.
And (again) stop the presses!

 

[wk057]

yes pretty soon I - will - be - typing - like - this :biggrin:

also note wk data was not done at high temperature where complex impedance is much lower. wk is well meaning and again I agree in NO WAY can the car be measured to produce 691HP on a dyno, but it appears he has no experience in pulse power system design using lithium cells (which are actually all hybrid capacitors in some respects).

Still have you on ignore, but someone PM'd me about this post.

First: lol.

Next: I've had over a dozen test cases running for the past several months doing cycle testing of Model S cells under various conditions. The internal impedance is nearly constant across all temperature ranges I've tested, right up until just before the cell explodes... which doesn't seem like a useful temperature for use in the Model S. One of my tests is one of my own design and is discharging and charging the cell as fast as possible while maintaining a constant cell temperature about 15C below the temperature where it's guaranteed to have a thermal event. I also am running that same test at a few other constant cell temperatures. Results have been pretty interesting and I plan on doing a write up on the results of all of my testing sometime in the next couple of months when I have enough data from some of the slower tests to better confirm the results. All using custom test equipment I designed and built specifically for testing these 18650 cells with high accuracy (and in pairs to have confirmation of the results).

Suffice it to say, under no conditions that I've tested does the internal impedance vary enough to make any notable difference in power output, good or bad. Even under maximum draw (basically a short circuit) at the millisecond level the cells do not deviate from my predicted results within a reasonable margin of error (+/- 1%). Therefore my graph represents reality, at the pack level, within +/- 1%.

Further, you have no knowledge of my background and expertise, so do not make such claims. I can, however, make the claim that you have no experience testing the Model S cells, the P85D power output, or anything directly factually related to this particular issue.

 

[Andyw2100]

Don't you all have day jobs?

I feel like this has become my day job.

And my night job, my middle of the night job, my weekend job...

 

[Dbitter1]

Don't you all have day jobs?

Some of us have fallen so far into the Cult of Tesla that this is more important than our day jobs...

 

[Discoducky]

I feel like this has become my day job.

And my night job, my middle of the night job, my weekend job...

Respect to those how have put so much thought into this topic as it is quite epic.

I follow, but just don't see how I could see this to be a bigger issue. Maybe I'll feel differently if my X doesn't perform as I expect it to.

 

[kennybobby]

But look...

 

[bonnie]

It is Saturday!!!

Not here!

- - - Updated - - -

I feel like this has become my day job.

And my night job, my middle of the night job, my weekend job...

Hah.

But I just don't get it, in all seriousness. It seems like after all these posts where people have repeatedly stated their opinion agreeing or disagreeing, if you're a disgruntled customer, then the discussion at this point should be between you and Tesla. Who cares if someone else thinks you're right or you're wrong?

Respect to those how have put so much thought into this topic as it is quite epic.

I follow, but just don't see how I could see this to be a bigger issue. Maybe I'll feel differently if my X doesn't perform as I expect it to.

I'm with you.

 

[Max*]

Who cares if someone else thinks you're right or you're wrong?

 

[dsm363]

If you start with "if (false) { ... }" or "if (suspect_hypothesis) { ... }" then the rest of the statement could be all kinds of fantasy that really is just intellectual, um, "focus on self". Sorry, it's an engineering / first principles thing.

Also, words like "majority" are often used to attempt to bolster an argument and force people into sides. Generally, I find this counterproductive as it creates conflict and distracts from the merits of the discussion.

You just used the word 'often' to bolster your argument. I'm tuning the rest of the post out.

 

[kennybobby]

With respect to who modified the wiki:

Eldon Technology Limited, Europe's foremost electronics design house, employs over seventy people, the majority being directly involved in the design and development of electronic based product on behalf of World wide customers. Most of the work is in the design of consumer electronics products such as analogue and digital televisions, satellite receivers and set top boxes as well as application specific computer monitors.

whois 212.250.100.69

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Organization: RIPE Network Coordination Centre (RIPE)
RegDate: 1997-11-14
Updated: 2009-03-25
Comment: These addresses have been further assigned to users in
Comment: the RIPE NCC region. Contact information can be found in

ResourceLink: whois.ripe.net
OrgName: RIPE Network Coordination Centre
OrgId: RIPE
Address: P.O. Box 10096
City: Amsterdam
StateProv:
PostalCode: 1001EB
Country: NL

inetnum: 212.250.100.64 - 212.250.100.127
netname: ELDON-TECHNOLOGY-LTD
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country: GB
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status: ASSIGNED PA
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created: 2010-04-19T14:55:15Z
last-modified: 2010-04-19T14:55:15Z
source: RIPE # Filtered

 

[flathillll]

Still have you on ignore, but someone PM'd me about this post.

First: lol.

Next: I've had over a dozen test cases running for the past several months doing cycle testing of Model S cells under various conditions. The internal impedance is nearly constant across all temperature ranges I've tested, right up until just before the cell explodes... which doesn't seem like a useful temperature for use in the Model S. One of my tests is one of my own design and is discharging and charging the cell as fast as possible while maintaining a constant cell temperature about 15C below the temperature where it's guaranteed to have a thermal event. I also am running that same test at a few other constant cell temperatures. Results have been pretty interesting and I plan on doing a write up on the results of all of my testing sometime in the next couple of months when I have enough data from some of the slower tests to better confirm the results. All using custom test equipment I designed and built specifically for testing these 18650 cells with high accuracy (and in pairs to have confirmation of the results).

Suffice it to say, under no conditions that I've tested does the internal impedance vary enough to make any notable difference in power output, good or bad. Even under maximum draw (basically a short circuit) at the millisecond level the cells do not deviate from my predicted results within a reasonable margin of error (+/- 1%). Therefore my graph represents reality, at the pack level, within +/- 1%.

Further, you have no knowledge of my background and expertise, so do not make such claims. I can, however, make the claim that you have no experience testing the Model S cells, the P85D power output, or anything directly factually related to this particular issue.

Wrong. The internal impedance does vary with temperature enough to make a very noticeable difference in pulse/burst power. Not enough of a difference to measure 691HP on a dyno, but that is besides the point. Why else would the Ludicrous cars have a MAX BATTERY POWER setting that heats the cells!

Any yes I do have knowledge of your background. You r a daytrader who has been in trouble before

lol

I do have a custom pack made from Tesla cells and yes they perform best when hot (as any EV drag racer knows). Here is where I got them from:

"-DCIR falls significantly at higher temperatures. This helps to self limit thermal build up of the... as the cell heats up, it tends to actually produce less heat!
-Panasonic NCA cells exhibit significant "surface discharge," that is, they perform well in bursts, where DCIR is lowered for a short period of time after a rest."

 

[Canuck]

"You must spread some Reputation around before giving it to flathillll again."

 

[sillydriver]

More misinformation. The P85D battery is incapable of putting out 515kW.

WK, please say a bit more about your chart. Is this your calculation from measurements you made on cells? Your text implied they are P85D cells. Should the curves on cells with the P90D chemistry be higher? Either way, with 600 HP for 100% SoC at 1500 Amps, that would seem to have positive implications for further improvements in performance for both cars.

 

[P85DEE]

Glad to see you guys making progress towards getting this matter hashed out.

 

[P85DEE]

You know guys, I learned a long time ago about SAE J1349 Certification, http://www.sae.org/images/logos/j1349-certified-power.gif

I tend to believe that had a lot of you learned of it earlier, it could have saved a lot of time, trouble and misunderstanding with regard to this matter.

You see, for years, auto manufacturers have sold cars based upon "horsepower numbers" and have "fudged" those numbers for marketing purposes, and for their own benefit. Several techniques have been utilized over the years.

But back in 2005, somewhat of an end was put to the shenanigans. It is a shame that so many in here were unaware of SAE J1349 Certification.

It came into existence in an effort to make it easier for a consumer to know what he was getting.

Insight into SAE J1349 certification can be gained by reading SAE What? - Technologue - Motor Trend

What really caught my eye in this article was "The certified output must be within one percent of the dynamometer output. Of course, ringer engines could easily be slipped through this process, but by certifying an engine the manufacturer guarantees all production engines will produce within two percent of the rated output (Europe allows five-percent deviation)."

And

Larry Webster: Horsepower Confusion and Resolution Car and Driver
What struck me here was"...Since minute differences in the dimensions of engine components that naturally occur during series production—the compression ratio could be a smidge higher in one engine versus another—can result in two identical-looking engines making slightly different horsepower, the SAE allows a one-percent tolerance between the number that the witness observes and the horsepower rating that a manufacturer chooses to publish....

Now, why is all of this important??? Well I'm glad that you asked.

I want each of you to take a good look at that parts in red above.

The Certified output must be within 1% of the dynamometer output......one percent tolerance between what the WITNESS observes, and what the manufacturer chooses to publish.

I've been an owner of performance vehicles for a good part of the time since I have had a driver's license. Error on my part, but I could not imagine how purchasers of a performance vehicle such as this one, were not at all familiar with SAE J1349 Certified Horsepower, which was started nearly 10 years prior to the introduction of the P85D. I could not understand how so many would not have known better.

I was conditioned years ago, to take manufacturer's "horsepower" claims with a large grain of salt......and in later years, not to not take them at all unless I saw that http://www.sae.org/images/logos/j1349-certified-power.gif emblem. 2005 drove that lesson even further home.

Why???? Because I know, and knew earlier, how manufacturers play games with "horsepower" numbers to sell cars.

Thus when I bought my P85D, and saw "horsepower motor power", first thing I'm wondering is "WTF is that? Where is the SAE J1349 Certified Horsepower Emblem?".... And knowing what I knew right off the bat, that UNLESS I saw http://www.sae.org/images/logos/j1349-certified-power.gif, well then all bets were off as to if it actually had the horsepower that the manufacturer claimed.

I bought anyway, knowing that, and not caring that the SAE Certified Horsepower emblem was absent. Why? Because I was only interested in the bottom line performance metrics that I was interested in. It fit that bill. The performance capabilities, trumped the presence of that logo. Had "horsepower" been the be all and end all for me, well then it would need to have the SAE J1349 emblem on it. But horsepower was NOT the be all and end all for me when it came to this car. Performance in the metrics that interested me was.

Indeed, to this day, unless you see http://www.sae.org/images/logos/j1349-certified-power.gif, well then don't trust it.

This is a big part of the reason why this issue is utterly moot to me.

ANY manufacturer, and I do mean ANY manufacturer, who does not have http://www.sae.org/images/logos/j1349-certified-power.gif in conjunction with his horsepower claims, I don't care whether it's Dodge, Ford, BMW, Mercedes, etc.....any car that I see with a horsepower claim listed in it's ad copy, if it does not have

http://www.sae.org/images/logos/j1349-certified-power.gif attached to it, well then I know better than to take the number at face value. No other independent and neutral SAE witness saw it, and can vouch for it. Thus I cannot trust it.

Any car manufacturer talking to you about "horsepower", in any passenger car, I'm here to tell you right here and right now, consider it utter BS unless accompanied by http://www.sae.org/images/logos/j1349-certified-power.gif , I don't care which car manufacturer it is.

I knew going in, because I was familiar with J1349 Certified Horsepower, that because that logo was missing in Tesla's web page description of the P85D that I was planning on buying, that in effect, I was buying the car on it's performance merits and performance metrics, which were important to me, , as opposed to any horsepower number.

You purchase any car, placing an emphasis on horsepower, if it does not have that J1349 Certified Horsepower, take a look at it again to familiarize yourself with it, http://www.sae.org/images/logos/j1349-certified-power.gif well then IF you are making a purchasing decision based in whole, or in part, on "horsepower", then you're on you own.

About - Certified Power (SAE J1349 and J1995) - SAE International

"The new voluntary SAE power and torque certification procedure ensures fair, accurate ratings for horsepower and torque as it uses third-party certification," said Queen. "SAE technical standards level the playing field, and this certification procedure is just the latest example of the value SAE has offered over the past century." To tout power and torque ratings as "SAE-certified," engine manufacturers must have an SAE qualified witness watch over the entire testing procedure to ensure that it is conducted in conformity to SAE standard J1349®. Third-party witnessing is the main provision of J2723. An existing SAE standard, J1349®, spells out how the actual testing is to be done. J1349® was updated last year to eliminate some ambiguities that allowed engine makers to cite power and torque ratings higher than the engine's actual capabilities..."

If "horsepower" is your bag, if "horsepower" is what you're opening your wallet for, if you're buying a car in whole or in part, because of it's "horsepower", well then you don't need to buy if that logo is absent. You have to ask yourself why the manufacturer elected not to participate in this program, if he hasn't. And if he hasn't, well then you cannot hang your hat on his numbers. It's as simple as that.

Also, don't tell me that this only applies to ICE vehicles, when so many of you have argued "horsepower is horsepower".

If that is true, well then if you buy without that SAE J1349 Certified Horsepower logo in place, I don't care what it runs off of, electricity, gasoline, water, etc., you simply cannot be sure just how much horsepower it has.

That logo, prevents an auto manufacturer from just telling you anything when it comes to "horsepower".

If you did not know before, something that I learned nearly 10 years ago, well then you know now.

That's part of the whole point of J1349 Certified Horsepower. To help consumers of passenger vehicles in their purchasing decisions where horsepower is involved , so that they know what they are getting. It's been here for years. If you didn't know about it, well then it's on you. In part because horsepower, is horsepower.

 

[jcaspar]

Long post! Here is an article on this by Car and Driver on this subject. Shows how some manufactures over rate their cars (Porsche, Audi) and others under rate theirs (Dodge). Seeing Porsche and Audi's responses to why their cars don't produce what they claim shows there is still a lot of clouds in the picture.

 

[P85DEE]

That article looks familiar:biggrin:

Yes, my post was long. But it was to drive home a few points.

A. If you're buying a car for "horsepower", well unless it is SAE J1349 Certified horsepower, you absolutely don't know what you're getting.

B. If you call yourself a performance car enthusiast, a foregone conclusion if you are a P85D owner, and didn't know the above, well then you should have known it, because that Certification has been around now for 9-10 years.

How does a performance car enthusiast, buy a performance car, and NOT know, not have any idea whatsoever about SAE J1349 Certified Horsepower and that logo in this day and age?

C. Don't holler "I didn't get the horsepower I paid for" if you bought a car without that Certification, because that program was instituted in part to prevent manufacturers playing with the horsepower numbers. It "ensures fair, accurate ratings for horsepower and torque as it uses third-party certification..."


If you didn't do your due diligence when it comes to "horsepower" and manufacturer's representations of it, well then you only have yourself to blame.

 

[wk057]

Wrong. The internal impedance does vary with temperature enough to make a very noticeable difference in pulse/burst power.

You obviously have no knowledge of my experience. And I'm not a day trader (Bloomberg just assumed that based on some conversations we had about gaming TSLA volatility in the past).

Once again providing misinformation that I'm left to clean up after. You realize I have a battery pack made up of 15,984 Tesla Model S cells powering my house, right? Along with about 1000 additional cells in other modules and loose cells of the same that I've been using for other purposes, mainly testing cell longevity and performance at various SoC ranges, charge discharge rates, temperatures, etc.

Unfortunately your data is flawed for one reason or another. Not my place to determine that particular flaw, but your conclusions do not agree with my testing of dozens of cells.

I've run tests with the Model S cells at 6C discharge (about 20A) in millisecond pulses. The result? A graph that is a 1 kHz square wave that perfectly matches predictions based on the near constant IR of these cells and discharge capacity amounts as predicted based on the same data. I've been running tests on pairs of these cells for nearly 5 months now in various conditions. Without spoiling my final results paper on the matter, I will say that temperature has some effects on the cells, but not the ones you're trying to sell here. Until you've run the tests yourself I suggest you sit this one out.

Not enough of a difference to measure 691HP on a dyno, but that is besides the point.

Actually, that's entirely the point. Do you even know what the topic is anymore? Or did you get too lost in the kittens?

Why else would the Ludicrous cars have a MAX BATTERY POWER setting that heats the cells!

You mean the max battery power option that has no measurable effect on performance? Seems like smoke and mirrors to me, especially looking at my mountain of data that proves it's useless. Plus, you even conceded this in the quote directly above... then go on to contradict yourself.

I do have a custom pack made from Tesla cells

Oh, well in that case I'll be generous. CC charge at 1.5A to 4.07V. CV charge with a max of 1.5A with a 20mA cut to 4.1V. Pause for 15-20 minutes. CV charge to 4.2V with a 50mA cut. Pause 15-20 minutes. CV charge to 4.2V again, 30mA cut. Oh, and don't let the cell temp rise above about 20 C for the entire process. So far this is the method that has yielded the most IR deviation from standard (decrease) that I've measured and the highest amp discharge rates on the first fast discharge immediately following the end of the charge cycle. It's not much of a deviation though, and drops IR by maybe 5% or so for the first few mAh of discharge if done rapidly (~8C or so) until the cell warms up, then it's back to normal IR.

I've been wondering if there would be a way to do this to the P85D pack, but it's probably a PITA and would need to be done basically at the drag strip tree in order to make a difference since as soon as you start utilizing the cells the variation is gone.

and yes they perform best when hot (as any EV drag racer knows).

I would agree with most cells, but not the Model S cells.

Surprisingly their discharge IR is ridiculously constant. It does increase with cycle count, however.

Charging IR is another matter entirely, though. It is very temperature dependent, and it honestly has completely unexpected behavior with charge rates > 1.1C with regard to temperature. For example, at 50% SoC I can get these cells to *charge* at nearly 3C (that's the equivalent supercharging at 250 kW for those interested) of at one temperature, but literally explode within seconds at 1.1C at another starting temperature.

In any case, this discussion is more suited for another thread at another time.

On the topic of horsepower in the P85D, this doesn't do us much good except further prove the car can not produce 691 HP.

Back to ignore you go...

- - - Updated - - -

WK, please say a bit more about your chart. Is this your calculation from measurements you made on cells? Your text implied they are P85D cells. Should the curves on cells with the P90D chemistry be higher? Either way, with 600 HP for 100% SoC at 1500 Amps, that would seem to have positive implications for further improvements in performance for both cars.

As stated above, the graph is based on data I've collected from long term testing of the Model S cells. They're specifically cells from a P85 pack with < 500 miles, but I've confirmed the cells in the P85D pack are the same cells. I have no data on the cells from the 70/90 packs, but it's been assumed that the IR is a hair lower on those cells so it would make for a slightly better graph.

Keep in mind this is power available at the battery, not the motor shafts or wheels.