Tesla cuts 60kWh Model S, entry-level Model S is now 70D.

[JRP3]

What confirmation? His claim seems to be that the 70D gets more range than the extra 10kWh of batteries would provide, and that the extra range must come from reduced weight that results from higher energy density cells. I see no definitive confirmation of any part of that thesis.

We know battery chemistry is advancing, since we already know there are more energy dense cells available than the 3.2ah cells used in the S. We don't know if more energy dense cells are being used in the 70D or any other Tesla at this point in time.

 

[vgrinshpun]

You can choose to dismiss what Elon or others have stated... but we know that there have been many running changes (additional battery armor, for instance) along the way that materially change the weight of the car. Yet the manual's specification for curb weight hasn't been updated for each of those hundreds of times the vehicle has been changed. So relying on the exact manual curb weight spec ins't authoritative.



I'm not dismissing anything. I'm stating that assuming a change is weight MUST be due to battery chemistry differences and COULD NOT be due to any other change in the cars, despite the CEO stating that weight changes are taking place is a logical fallacy.

I repeat: correlation != causation



I made no mention of my opinion of the cells here[1], and most certainly didn't characterize anything as a "slam dunk". My point again is that there may be other factors accounting for weight change.


[1] Although as I have posted elsewhere, I do in fact believe the cells in the 70 are the same as the existing chemistry cells.

If your argument is that weight reduction mentioned by Elon is the reason for the decreased energy consumption per mile in 70D, the same effect should be observed in 80D. As I showed in my original post (with the graph) it is simply not true, as 80D does not have even close to (proportional) reduction in energy consumption per mile as 70D does. So, in order to avoid logical fallacy, one have to conclude:

1. Reduction of "hundreds" of pounds never actually happen
2. The abnormal decrease in energy consumption in 70D (as compared to other variants) can not be explained by reduction of weight that was mentioned by Elon (however large or small it actually was), because it would apply across the board to **all** variants, and reduction in energy consumption for 70D would have been in line with 80D, which it clearly is not.

 

[vgrinshpun]

This is key. Vgrin is saying new cells = lighter = more range. Elon is saying weight is not a large component of range, within the context of a 100 or 200 lbs. That is consistent with what we already know. Range does not change noticeably with a 200lb passenger compared to a single driver.

This is true **only** for travel with constant speed at perfectly level surface. It is verifiably **not** true for driving that involves acceleration/deceleration and change in elevation, as evidenced by the fact that based on EPA range Wh/mile for 60 is abot 10% lower than in 85. After all the difference in weight of 60 and 85 is "only" 223lbs, and, according to your logic the difference in energy consumption should be negligible.

What might better explain it is if the 70kWh pack is slightly over 70kWh and a bit more of the rated capacity is available for use. From tests the "85"kWh pack seems a bit under 85kWh, maybe the 70 is a bit over 70kWh. Maybe they are more comfortable using a larger percentage of pack capacity. There are simply a number of other possible explanations for the extra range besides new cells.

This indeed would be a one of the logical ways to explain out of proportion reduction in energy consumption in 70D, except the numbers do not work.

According to the Manual, as I posted before, the bricking reserve is about 5% of the battery capacity. In order to make numbers work and put 70D point shown on my chart squarely onto the orange line, one would need to "free" 3.6% out of the 5% bricking reserve and use it for range improvement. Assuming that TM would be OK to reduce bricking reserve from 5% to 1.4% is really a stretch. I also have hard time to believe that there is "rounding" reserve in the nominal battery rating of 70kWh. Once again, in order to move the needle you'll need to have this "rounding" reserve to be an order of magnitude larger than what can be reasonably assumed.

 

[JRP3]

This is indeed would be a one of the logical ways to explain out of proportion reduction in energy consumption in 70D, except the numbers do not work.

According to the Manual, as I posted before, the bricking reserve is about 5% of the battery capacity. In order to make numbers work and put 70D point shown on my chart squarely onto the orange line, one would need to "free" 3.6% of the bricking reserve and use it for range improvement.

What about using more of the other end as well, closer to 100% SOC? 1.8% more at the bottom and 1.8% more at the top.

 

[vgrinshpun]

What about using more of the other end as well, closer to 100% SOC? 1.8% more at the bottom and 1.8% more at the top.

Well, the reason that seems unlikely is the very same reason that you used to question my theory: if the battery cell chemistry/composition did not change, why would the battery utilization rate be *not* uniform across the board, for *all* the variants?

At the core of what we are trying to explain is an anomaly associated with the 70D energy consumption. So we need to find something, that would be unique to 70D and 70D only.

I really believe that my theory is the only one that withstood all the healthy and robust questioning that only this Forum can produce...

 

[JRP3]

Well, the reason that seems unlikely is the very same reason that you used to question my theory: if the battery cell chemistry/composition did not change, why would the battery utilization rate be *not* uniform across the board, for *all* the variants?

Because over time Tesla has grown more confident that the existing chemistry is robust enough to handle a slightly greater charge/discharge range. Maybe they've enable this in the new 70D but for various reasons aren't bumping up the 85's at this time. Not saying this is the case, but a possibility.

You have built a good case, but there are still enough unknowns that I remain unconvinced.

 

[HankLloydRight]

I really believe that my theory is the only one that withstood all the healthy and robust questioning that only this Forum can produce...

Only in your mind. There have been plenty of plausible and quite possible reasons for the differences as well as heathy skepticism on the questionable accuracy of your sources and your assumptions made only to support your conclusion.

Have you ever heard the notion: "The lady doth protest too much, methinks" ?

 

[vgrinshpun]

Only in your mind. There have been plenty of plausible and quite possible reasons for the differences as well as heathy skepticism on the questionable accuracy of your sources and your assumptions made only to support your conclusion.

Have you ever heard the notion: "The lady doth protest too much, methinks" ?

Give me your favorite, presumably "not questionable" explanation for abnormally low energy consumption in 70D. While at it, also provide a plausible explanation for the fact that Tesla "voluntarily" lowered EPA range for 70D from tested 245 miles to 240 miles shown on EPA sticker.

 

[Model 3]

Give me your favorite, presumably "not questionable" explanation for abnormally low energy consumption in 70D.

Until Tesla gives us the answer, no explanation is "not questionable".

While at it, also provide a plausible explanation for the fact that Tesla "voluntarily" lowered EPA range for 70D from tested 245 miles to 240 miles shown on EPA sticker.

To make a more clear marked difference between the 70D and the 85(D) so the 70D would not eat to much into the marked of the 85(D). While it was a clear difference between the 60 and the 85 it's less clear between the 70D and the 85(D) - the 70D has the same warranty, and has also the supercharger included. It also have a bigger battery and longer range then the 60. The range differneces is only 30 (25 for the 85 none-D) miles, without the "voluntarily" lowered EPA range it would be only 25(20) miles. Why buy a 85(D) when you can get the 70D for less money and almost the same range?

 

[WarpedOne]

Why then even increase the capacity if one fears the product would eat into another product sales too much?
what made them do that? Competition? I don't see any. Dual motor current demanDs? There is plenty other easier solutions. And why not simply increase just to 65? Or not at all? If they just increased the cell count, it is a trivial solution to that problem.
What made tesla increase capacity that much to endanger sales of higherpriced product and to understate range in an EV where one jumps through hoops to get another rated mile? This is a sure sign they had a pretty good reason to go to 70kWh pack.

it is much more sound reasoning that panasnic is already building nextgen cells that are to be produced in GF. There is enough of them for some packs, but not enough for thousand packs per week. And there still is production and supply of older tech cells.

tesla has tools and everythng for packs with x and y number of cells. x beeng number of cells in 85 and y number of cells in 60kwh packs. Using different number of cells would mean new tools and testing etc. just replacing the cells only needed the panasonic to do their RD. 100kwh packs are in the pipeline. And also the outcry of customers who were not able to order it. Model X will be introduced with 100kWh pack. You may call me on this prediction

 

[Model 3]

Why then even increase the capacity if one fears the product would eat into another product sales too much?

There is a balance between bringing in new customers who can not or will not take the price of the 85 models, and not to get too many to downgrade from 85 to 70.

You may call me on this prediction

I will, don't you worry

 

[WarpedOne]

There is a balance between bringing in new customers

Yes, there is. But first there must be a lack of customers. I haven't seen any clear sign of that anywhere.
70D is not there because of too low sells.

 

[Model 3]

70D is not there because of too low sells.

Yes it is. Too low sells of the 60kWh version of Model S. And just dropping the 60 and make the 85-none-D version the new base version would have increased the base price too much.

 

[HankLloydRight]

Give me your favorite, presumably "not questionable" explanation for abnormally low energy consumption in 70D. While at it, also provide a plausible explanation for the fact that Tesla "voluntarily" lowered EPA range for 70D from tested 245 miles to 240 miles shown on EPA sticker.

I don't need to find or create an competing theory in order to invalidate yours. I've explained several times how your source data is questionable, and your assumptions created to support your theory. You're simply trying too hard to prove a theory that really has very little actual support of the facts. I'm not privy to Tesla Motor's inner workings, so I'm not even going to try and guess why they changed the EPA rating. But new battery chemistry is one of many, many, possible reasons -- marketing being probably the most plausible one.

You even fabricated one of your data points because you needed it to fit your theory:

In order to update the chart I needed data point (energy consumption) for hypothetical 60D. Since this data does not exist, I used range data for 85D and 85 to obtain range for hypothetical 60D as follows: (270*208/265=212).

What is the *real* range for a 60D? In fact, immediately following your post, this was posted:

Not sure if it helps here, but when 60D was announced for a few days, Tesla claimed its range as 225 miles @65mph.

Are you using your fabricated 60D range of 212 in your theory, or did you update it to use 225 as Tesla claimed?

And you seem to ignore or discount what was reported concerning the 70D battery pack:

On page 3 of this article ( http://www.greencarreports.com/news/...e-model/page-3 ) posted today, David Noland says "A Tesla spokesman confirmed to me that the bigger battery capacity comes from more cells, not better ones."

 

[jvonbokel]

Why then even increase the capacity if one fears the product would eat into another product sales too much? what made them do that?

I have a (completely speculative and unfounded) theory that once they built the new motor (excuse me, "high efficiency electric drive unit", they did some modeling and/or testing to find the ideal battery capacity to hit some ideal point on an efficiency curve or the battery size/cost curve and came up with the 70D.

 

[32no]

I don't need to find or create an competing theory in order to invalidate yours. I've explained several times how your source data is questionable, and your assumptions created to support your theory. You're simply trying too hard to prove a theory that really has very little actual support of the facts. I'm not privy to Tesla Motor's inner workings, so I'm not even going to try and guess why they changed the EPA rating. But new battery chemistry is one of many, many, possible reasons -- marketing being probably the most plausible one.

You even fabricated one of your data points because you needed it to fit your theory:



What is the *real* range for a 60D? In fact, immediately following your post, this was posted:



Are you using your fabricated 60D range of 212 in your theory, or did you update it to use 225 as Tesla claimed?

And you seem to ignore or discount what was reported concerning the 70D battery pack:

The snark/snippiness on your part is unwarranted. I'm fairly certain vgrinshpun, or maybe someone else (I don't remember who) has already said that a non specified Tesla "spokesman" is probably a service center employee and isn't exactly a reliable source of information especially for something as seemingly secretive as these potentially new cells.

Also, driving range at 65 mph is different than EPA 5 cycle range, as can be clearly seen in this blog: Driving Range for the Model S Family | Tesla Motors

 

[HankLloydRight]

has already said that a non specified Tesla "spokesman" is probably a service center employee

"Probably"? Is this just a guess, or has this been confirmed in any manner?

 

[JRP3]

The reporter, David Noland, has done a lot of reporting on Tesla, is a Model S owner, and is probably the only person who has been able to upgrade their 60 pack to an 85, so if he says "Tesla spokesperson" it's probably not just someone at the local SC.

 

[HankLloydRight]

Also, driving range at 65 mph is different than EPA 5 cycle range, as can be clearly seen in this blog: Driving Range for the Model S Family | Tesla Motors

So fabricating a number based on the 85/85D range is better or more acceptable? Maybe the 225 number isn't valid because it isn't the 5 cycle test..so I'd say neither number can be used for this analysis. Throw them both out. But just because you can invalidate the 65mph range number doesn't automatically validate the other one.

 

[scaesare]

If your argument is that weight reduction mentioned by Elon is the reason for the decreased energy consumption per mile in 70D, the same effect should be observed in 80D. As I showed in my original post (with the graph) it is simply not true, as 80D does not have even close to (proportional) reduction in energy consumption per mile as 70D does. So, in order to avoid logical fallacy, one have to conclude:

1. Reduction of "hundreds" of pounds never actually happen
2. The abnormal decrease in energy consumption in 70D (as compared to other variants) can not be explained by reduction of weight that was mentioned by Elon (however large or small it actually was), because it would apply across the board to **all** variants, and reduction in energy consumption for 70D would have been in line with 80D, which it clearly is not.

You seem unwilling, or unable, to grasp my premise. I've said nothing about the reason for 70D energy consumption. Please search for those terms (or similar) in my posts. You won't find them.

So again for clarity, I am responding to your post wherein you stated:

According to the Car and Driver instrumented test (thanks to Anticitizen13.7 for posting) the weight of the 70D is 4608lbs, while the weight of now defunct 60D was essentially the same - 4597lbs according to the Road & Track data back from Oct. 9 article published right after the "D" event. This is consistent with my theory that the battery in 70D weighs the same as the battery in 60, contains the same quantity of cells, but each cell, due to higher volumetric and gravimetric energy density contains about 16.7% more energy. This is consistent with the conclusion that 70D contains new generation of the cells,

(emphasis mine)

Again, there is testimony directly from Tesla sources (Elon) that the car's weight is being reduced due to engineering change,

There is direct evidence that the published curb weight does not track all car changes (such as additional battery armor)

There have been reports by folks here (referenced in this thread) that they have been told by sources familiar with the internals that the chemistry has not changed.

Hence, there are significant arguments against the hypothesis that any weight data supports the idea of differing cell chemistry in the 70D pack.