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

[cynix]

You cannot drain it to 0 (zero) within the system (i.e. driving the car)... the software will shutdown components incrementally to prevent bricking the battery.

I didn't say you can drain it to 0 by just driving the car. If you really wanted to, you could leave the car in brick protection mode and the battery will eventually drain to 0. Sure it may not be very useful to the driver, but at least it's achieveable in the car as sold with no modification. This is not the case with the 691 hp motor rating, because it is simply not achieveable in the car as sold with no modification.

Anyway, why are we talking about the battery? This thread is about the car's power output, not battery capacity.

 

[sorka]

Yes, it does.

Lets do some calculations based on the system parameters of the Model S P85D... and some googling.




further on...


Through Google I get that the nominal* voltage of a Model S battery pack is "375 volts" per Tesla spec (link Technical Battery Discussion | Forums | Tesla Motors )


to get 691 HP we need 745.7 * 691 = 515278 watts ~= 515kW
P = I*V
515kW = I * 375V
I = 515Kw/375V
I = 1374 A


From the July Ludicrous announcement we know that the OLD fuse can handle around 1300 A...





Based on that, we can say that the "old system" (pre smart fuse) has 691 hp "at some point".


What I am saying (before the corrections start coming in) is: the pre-ludicrous system (Model S P85D has the hardware limits of 691 hp).
From the call on Ludicrous upgrade... the focus on fuses was that the failure band is too wide and they needed something more precise+consistent... and you cannot get the consistent precision with passive material... so again smart fuse would actively monitor and blow at the set 1500 A limit... so the true limit of the old system is higher then 1300 (not claiming that it was 1500 pre Ludicrous) but because of the nature of traditional fuses they had to limit at 1300A to cover their bases.




* Now, one can argue that the 1300 vs 1374 is substantial (~5%).
All the calculations were with nominal voltage... we know from this forum that the peak voltage of the Model S 85 kWh packs is over 400V ( Model S Battery Voltage? )


P = I*V
P = 1300A * 375V = 487500 watts ~= 487kW
487500 / 745.7 = 653.75 HP < 691 HP


If we just do the same calculation with 400V... which is still lower then the peak voltage reported on this forum.
P = 1300A * 400V = 520000 watts ~= 520kW
520000 / 745.7 = 697.3 HP > 691 HP



So,

is correct, the system does have 691 hp...


In addition to losses from shaft to wheel, I think the blog post by JB Straubel highlights why it cannot produce the combined HP...

The voltage drops to 320 volts at 1300 amps which = 416KW which is exactly 1KW higher than the highest recording "power" reading from the REST API. So no, the system doesn't have 691 hp.

 

[mikes_fsd]

The voltage drops to 320 volts at 1300 amps which = 416KW which is exactly 1KW higher than the highest recording "power" reading from the REST API. So no, the system doesn't have 691 hp.

Yes, known as system losses...

The system does not produce ​691 hp.

Trying to use forum search without success here...
There is a thread somewhere with the measured/calculated internal resistance numbers for the battery cells. If anyone has the link to that thread, it would be amazing not to have to use the forum search ever again.

 

[vgrinshpun]

Had I gotten the range of a 85D as well I would have taken such an offer in a heartbeat


No, and I never said so. But the same argument can be used the other way around. There is no evidence it isnt limited is there? Yet you and others use current performance metrics of the 85D as proof for these statements. I am pointing out that such a comparison is by default flawed since you dont know what limits are forced or not on the 85D by software.

The only actual evidence we do have is that the 85D and the P85D was indeed both limited at launch. So back to my point that all of this is speculation as long as you dont have proof that the 85D isnt limited anymore.

Ref the 85D vs P85 acceleration: how do you know the weight-diff isnt purely offset by the added traction of the front motor? Once again no proof I assume, but mainly speculation sold as "facts"..

All might be correct in these speculations, but you really cant prove it.

Wrong assumption on your part.

The P85 is able to put out all available torque from the rear performance motor to the pavement, as evidenced by this vbox chart posted by Sorka. This means that all 443 lb-ft of torque available in P85 is converted to the acceleration. So the increased weight of the 85D can only be offset by the additional 10% of the torque available over the torque in P85 (486 lb-ft vs. 443 lb-ft in P85).

- - - Updated - - -

What? (one questionmark) These are the numbers that was handed to me at delivery in march 2015 of my P85D which was bought advertised as 700 hp - There was no revision of any numbers at that time, so please do elaborate some more on how you think these numbers are not correct?

I do not know when you ordered your car - you really should provide this data before screaming out any questions.

Upon the original launch the P85 was advertised at 691 motor hp (515kW). That included 470 motor hp (350kW) for rear and 221 motor hp (165kW) for front.

At some point later on (again, there is a post by Stopcrazypp somewhere listing specific dates) the motor hp ratings were revised to what you say is shown on your CoC (would be nice to see actual picture of your CoC with the date of issue), i.e. 470 motor hp (350kW) rear and 258 motor hp (193kW) front. These two add to a total of 728hp, which was also contemporaneously shown on the Tesla website.

 

[Johan]

Dudes, we've been over the battery capacity analogy and I'm somewhat inclined to agree with flathill here, it's a bit of a double standard to just accept the 85kWh rating but call Tesla deceitful liars when it comes to rating the car at 691 hp. The Thinkosaurus did have something to say about it:

(At the time I made this 550 hp was an estimate that was sort of agreed upon as an upper bound for the battery limitation).

 

[vgrinshpun]

Wow, with all the faulty analogies being thrown around the "691" threads this might be one of the very few true ones. :biggrin:

 

[Andyw2100]

Dudes, we've been over the battery capacity analogy and I'm somewhat inclined to agree with flathill here, it's a bit of a double standard to just accept the 85kWh rating but call Tesla deceitful liars when it comes to rating the car at 691 hp. The Thinkosaurus did have something to say about it:

(At the time I made this 550 hp was an estimate that was sort of agreed upon as an upper bound for the battery limitation).

It would appear the Thinkosaurus is lousy at math.

Leaving aside for the moment that the Thinkosaurus, being a dinosaur and all, clearly can't be expected to grasp the difference in the two situations, the Thinkosaurus is either really, REALLY bad at math, or has a bizarre definition of "same."

The battery actual vs. stated work out to 95.4%.
The horsepower actual vs. stated (from the picture) work out to 79.6%.

The Thinkosaurus concludes the situations must be the same? A shortage of less than 5% vs. a shortage of more than 20%?

Bad Thinkosaurus!

Edit: And just so the Thinkosaurus has something to think about, here's just one of the reasons the situations are completely different:

Tesla was clear in giving the range of the P85D, in miles. (We can quibble about that somewhere else, but for purposes of this discussion, they were clear enough.) Tesla provided different numbers at different times, but I believe at one point the number was 285 miles on a charge, at 65 MPH. So the amount of usable kWH in the battery is not relevant. It would be an entirely different situation if Tesla had said "You'll get 3.52 miles per kWH at 65 miles per hour", and then let us do the math, multiplying 3.52 X 85, when in actuality they were multiplying 3.52 X 81.1. Because in that case we'd wind up with an expectation of more range than the car was actually capable of. BUT THAT'S NOT WHAT THEY DID! They actually told us how much range to expect, so the amount of battery used vs. unused to achieve that range is not relevant.

This is completely different from the horsepower issue, where we had no idea that we were not getting the 691 HP.

 

[Johan]

It would appear the Thinkosaurus sucks at math.

Leaving aside for the moment that the Thinkosaurus, being a dinosaur and all, clearly can't be expected to grasp the difference in the two situations, the Thinkosaurus is either really, REALLY bad at math, or has a bizarre definition of "same."

The battery actual vs. stated work out to 95.4%.
The horsepower actual vs. stated (from the picture) work out to 79.6%.

The Thinkosaurus concludes the situations must be the same? A shortage of less than 5% vs. a shortage of more than 20%?

Bad Thinkosaurus!

That's true, he flunked basic algebra on the account of some severe AGW (Asteroid induced Global Winter).

Either way, disregarding the numbers, the principle is very, very analogous. Yet I'm not seeing threads with hundreds of post and threat of legal action from owners who bought a car with an advertised 85 kWh battery where one could never, ever, for any practical purpose access all of those 85000Whs.

Even the super annoying fact that the Wh/mile rating given to the user on the dash does not seem to work in the real world seems not to annoy people the way the 691 issue does. Example: 85 kWh (the rating of the car) divided by 300 Wh/mile (my average according to the display) = I will run out of charge after 283.33 miles, right? ... Or not?

 

[Andyw2100]

That's true, he flunked basic algebra on the account of some severe AGW (Asteroid induced Global Winter).

Either way, disregarding the numbers, the principle is very, very analogous. Yet I'm not seeing threads with hundreds of post and threat of legal action from owners who bought a car with an advertised 85 kWh battery where one could never, ever, for any practical purpose access all of those 85000Whs.

Even the super annoying fact that the Wh/mile rating given to the user on the dash does not seem to work in the real world seems to annoy people the way the 691 issue does. Example: 85 kWh (the rating of the car) divided by 300 Wh/mile (my average according to the display) = I will run out of charge after 283.33 miles, right? ... Or not?

It looks like you were replying as I was editing. (I can tell because of the word I chose to soften.) But I'm guessing that means you didn't see my addition, explaining why I think the situations really are not at all comparable.

 

[stopcrazypp]

They actually told us how much range to expect, so the amount of battery used vs. unused to achieve that range is not relevant.

This is completely different from the horsepower issue, where we had no idea that we were not getting the 691 HP.

An example of analogy that might not go the way you want. There are those that argue Tesla provided 0-60 and 1/4 mile and that is what matters in performance, not the battery-limited hp number. The people who got in trouble in terms of expectations were those that extrapolated performance themselves from the motor power number.

The argument about range vs usable capacity seems to be similar. If you extrapolate using the 85kWh and Wh/mi number displayed on the car (as many have done, there was a long thread about this), then you end up disappointed because you run into the usable capacity and reserve range issue.

 

[Johan]

It looks like you were replying as I was editing. (I can tell because of the word I chose to soften.) But I'm guessing that means you didn't see my addition, explaining why I think the situations really are not at all comparable.

I see your point. So we come back to the basic question of what you can do with horsepowers in themselves, except drive the car quickly between 0-60, a quarter mile or some other metric. I'm sensing this is the core issue: you want the dyno slip to read "peak hp: 691" even though you're not expecting better performance. Then you will be "happy"?

 

[Andyw2100]

An example of analogy that might not go the way you want. There are those that argue Tesla provided 0-60 and 1/4 mile and that is what matters in performance, not the battery-limited hp number. The people who got in trouble in terms of expectations were those that extrapolated performance themselves from the motor power number.

But those were just two stats.

While I'm not one of the people who actually had any sense of what a 691 HP car should feel like when accelerating from, say, 60-80, there were plenty of people buying P85Ds that did. As I've said before, the main point that struck home with me was Musk saying at the D announcement (which I watched many times before ordering) "half again as much power." That DID mean something to me because I knew how happy everyone was with the power of the base car he was using for comparison, so a car that was 50% more powerful than that would have to be a beast!

I see your point. So we come back to the basic question of what you can do with horsepowers in themselves, except drive the car quickly between 0-60, a quarter mile or some other metric. I'm sensing this is the core issue: you want the dyno slip to read "peak hp: 691" even though you're not expecting better performance. Then you will be "happy"?

No, not at all.

I fully recognize that there is drive train loss. I think most people who were knowledgeable about these things at the time expected 691 HP at the motor shaft. I think now more people understand the issues than did before, and I expect the majority of people who have become educated on this understand that 691 HP at the wheels was never a possibility, and not something we should expect. 691 HP somewhere in the system, though would be nice.

Edit: And for Johan--being completely honest, I'm not sure how often I would even notice the difference in HP, as I don't drive all that aggressively. But it's the idea of having paid for something and not received it that doesn't sit well with me. In one of the other threads I came up with an analogy that I think is appropriate to the situation. I'll go find it, and copy it below.

I also have another analogy for those here who don't think it's appropriate for us to ask Tesla to make this right to think about.

You are in charge of taking a few people from your company, and several clients, out to dinner. You select a very expensive restaurant, and order four bottles of expensive wine for the table. You happen to be away from the table for a couple of minutes when the wine is served, so the bottles are not actually presented to you, for your approval. You're not a great wine connoisseur anyway, so perhaps even if they had been shown to you, you wouldn't have remembered the exact name and vintage of the french wine that you ordered. Everyone is enjoying their meal, and their wine, but part way through the meal one of your staff, who happens to know a great deal about wine, tells you quietly that he thinks the wine brought to the table is not the wine that you ordered, but actually a somewhat significantly less expensive wine. All other aspects of the meal were fantastic! Everyone had a great time, and couldn't stop talking about how great the food was. Some even said how much they enjoyed the wine. Later the bill is presented, and you see that it includes charges for the more expensive wine that you ordered. You inquire, quietly, so as not to let any of the clients know anything is wrong, as to which wine was actually served. The waiter goes away, comes back a couple of minutes later, and says he is very sorry, but you are correct, and the wine served was actually the less expensive wine. However, since the bill has already been prepared, there is really nothing he can do: you'll have to pay the higher amount, for the more expensive wine you did not actually receive, even though there is a simple and obvious solution to the problem readily available.

Is this acceptable? Would the people suggesting we give Tesla a pass also give the restaurant a pass? If not, why do you think we should let Tesla give us less than we paid for?

 

[darthy001]

Don't we need to wait for a decision still in Denmark to determine this? Or has it been decided already against Tesla?

The danish version of teslamotors.com didnt have the words "motor power" or any translation of it either for several weeks if not months after the D-event. So the danes that ordered early on didnt have that piece of information when ordering. They where simply sold "700hp performance" directly translated. One of the few points not discussed here anymoe, but often conveniantly "forgotten" by some of the regulars.

 

[MikeBur]

Are we there yet!?

There's a continuum between constructively-critical debate and constantly repeating the same data in the hope that someone will concede.

Can we lock the thread until we determine next new information please? I know I should just ignore the thread, rather than reading it - never mind feeding it - though I obviously have unencumbered hope there may be new data in one of the posts

Just a thought....

 

[flathillll]

at least we can all agree the p85d does not produce 691hp but it does have a 691hp rating which could mislead some people.

the reason it is important to be precise is because this case will be going to court or arbitration.

we also all agree the 85kwh rating is also misleading to everyone, but that is OK because all EVs use this rating system, and because there are a lot or really good reasons to simply state the nominal pack capacity when describing it, just as there are many good reasons Tesla has chosen to spec hp during the p85d launch (see JB blog post). mercedes also rated their 4 motor EV the same way (did not state usable hp) so there is precedent.

 

[Johan]

I fully recognize that there is drive train loss. I think most people who were knowledgeable about these things at the time expected 691 HP at the motor shaft. I think now more people understand the issues than did before, and I expect the majority of people who have become educated on this understand that 691 HP at the wheels was never a possibility, and not something we should expect. 691 HP somewhere in the system, though would be nice.

Edit: And for Johan--being completely honest, I'm not sure how often I would even notice the difference in HP, as I don't drive all that aggressively. But it's the idea of having paid for something and not received it that doesn't sit well with me. In one of the other threads I came up with an analogy that I think is appropriate to the situation. I'll go find it, and copy it below.

Right, I disregarded the drivetrain loss there. Let me put it this way: Assuming the car performed exactly the same that it does today, but when tested on a dyno the slip shows the peak horsepower to be whatever value one would expect it to show being a car actually outputting 691 hp from the motor but after drive train losses, would you then be happier with the car than you are today?

I like your analogy and in many ways it goes to prove that there are some fundamental inconsistencies in our cognitive machinery: if the wine was great it was great, right? Why does it change anything that you find out later that it wasn't the bottle that was quite as expensive as you thought? Yet somehow it does alter our perception of value retrospectively. This cognitive phenomenon is apparently hard wired in us humans, and it's one of those deep rooted biases that we just seem to have a very hard time getting around. That's too bad because we would likey all be happier as people if we were able to not think this way. I'm not saying you're not in your right to feel the way you feel, I'm just saying I wish (for your sake) you could stop feeling that way and instead enjoy the wonderful car you're driving. I know you're saying you do enjoy it very much, but it's clear from your's (and other's) postings in this thread that the reveleation of the "missing horsepowers" have tainted your pure enjoyment of the car. Without the car having changed one bit.

 

[Auzie]

Are we there yet!?

There's a continuum between constructively-critical debate and constantly repeating the same data in the hope that someone will concede.

Can we lock the thread until we determine next new information please? I know I should just ignore the thread, rather than reading it - never mind feeding it - though I obviously have unencumbered hope there may be new data in one of the posts

Just a thought....

I think penny might be finally dropping for some people

The hardest thing might be to publicly reverse the staunchly defended positions, so we may not see that happening

 

[Johan]

I think penny might be finally dropping for some people

The hardest thing might be to publicly reverse the staunchly defended positions, so we may not see that happening

Do you mean as in one side is right and one side is wrong or as in anyone who held a strong polarized view was wrong, since the issue has no clear right or wrong?

 

[Andyw2100]

Right, I disregarded the drivetrain loss there. Let me put it this way: Assuming the car performed exactly the same that it does today, but when tested on a dyno the slip shows the peak horsepower to be whatever value one would expect it to show being a car actually outputting 691 hp from the motor but after drive train losses, would you then be happier with the car than you are today?

I can't say to what extent I would notice the difference. My honest guess is that I would notice the performance difference very rarely, if ever. (My wife drives the car a lot more than I do, and I can assure you that she would never notice the difference.) That said, I would definitely be happier in that I would not feel like I had paid for something I had not received.

I like your analogy and in many ways it goes to prove that there are some fundamental inconsistencies in our cognitive machinery: if the wine was great it was great, right? Why does it change anything that you find out later that it wasn't the bottle that was quite as expensive as you thought? Yet somehow it does alter our perception of value retrospectively. This cognitive phenomenon is apparently hard wired in us humans, and it's one of those deep rooted biases that we just seem to have a very hard time getting around. That's too bad because we would likey all be happier as people if we were able to not think this way. I'm not saying you're not in your right to feel the way you feel, I'm just saying I wish (for your sake) you could stop feeling that way and instead enjoy the wonderful car you're driving. I know you're saying you do enjoy it very much, but it's clear from your's (and other's) postings in this thread that the reveleation of the "missing horsepowers" have tainted your pure enjoyment of the car. Without the car having changed one bit.

I understand what you are saying. I wouldn't say the horsepower issue has changed the way I feel about the car, but it, and some other things, has definitely changed the way I feel about Tesla. I'm not in the "I hate Tesla" camp, but I just don't feel nearly as warm and fuzzy towards Tesla as I did when I first ordered the car. Back then I was under the impression that Tesla was this awesome company that put customer service above everything, and that any small issues that arose would easily be dealt with. Unfortunately I've now learned otherwise. Does that mean I won't ever purchase another Tesla? No, it doesn't. Tesla just isn't on the pedestal in my mind that they were on a year ago, that's all.

It's unfortunate.

What's even more unfortunate is that I know I'm not alone in feeling this way.

 

[flathillll]

I did some detective work...

the Models S wikipedia entry was updated to indicate the battery limited HP months before JB's blog post confirmed the battery limited HP. I bet the IP links to a Tesla employee. No big deal but interesting none the less

Tesla Model S: Difference between revisions - Wikipedia, the free encyclopedia

Tesla Model S: Difference between revisions - Wikipedia, the free encyclopedia

User contributions for 212.250.100.69 - Wikipedia, the free encyclopedia

"Total motor power specification, battery power limited to less"