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Degradation or change in software?

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
In december of 2016, 15 months ago, TeslaFi was showing estimated ranges at 100% of 251 rated miles after each charge to 90%. Cool that it does this. I never subscribed to TeslaFi until now. I have whole in the data from then until now.

Today, TeslaFi estimates 245 miles at 100% after a 90% charge.

So basically, the first 2 years I lost 2 miles of range and the last year I've lost 6 miles of range.

Has anyone noticed a sudden decrease in rated range with any software update in the last year?
 

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
i-6S6tzvN-X2.png


So is 76.1 the current estimated capacity? Is that without the anti brick buffer?
 

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
Yea, so this is confusing. 76.1 at 300 wh / mile (which is the rated per mile for the P85D) is 253.3 miles of rated range, so either this isn't the estimate, or the estimate is wrong unless I've had no degradation. Pretty sure it also said 76.1 the very first time I ever ran TM-SPY.
 

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
I should have mentioned that 253 rated miles is what the P85D is when new.

So 300 wh / mile, 76.1, and 245 doesn't add up if rated is simply capacity / .3 = 251 when reported rated is 245.
 

lymex2018

Member
Feb 4, 2018
132
145
China
i-6S6tzvN-X2.png


So is 76.1 the current estimated capacity? Is that without the anti brick buffer?
That 76.1 is without the anti brick buffer, but with the 4kWh zero mile buffer. That is to say, if you drive the car to zero mile, that "Remain" should be 4kWh. However, the figure may be reduced as the battery degrade. There is a Kman's video showing 2.5kWh left at zero mile. If that is also the case, then the estimated miles should be (76.1-2.5)/0.3=245.3, same as the TeslaFi's.
kman0.png
 

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
Interesting. Although the 0 mile buffer was positively disproved by Jason (wk057) and the 85 pack is 81kWh physically with 77 usable. i.e you'll never find anyone with any 85 pack that ever shows higher than 77 kWh to the right of "Pack".

Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)
Tear down of 85 kWh Tesla battery pack shows it could actually only be a 81 kWh pack [Updated]


Kman's is a 90 with a reported 80.6 but if it's an early 90 we know those degraded very quickly after just a few thousand miles.
 
  • Informative
Reactions: Rocky_H

lymex2018

Member
Feb 4, 2018
132
145
China
I once reached 0 mile just before arriving at a supercharger. Here is the screen shot before actual charging.
Screenshot_20171228-130734s.png

3.4kWh left when the dash display 0%, and the SOC of TM-Spy is 4.8%.
There are some discussions here about the zero mile buffer.
 

apacheguy

S Sig #255
Oct 21, 2012
5,076
1,238
So Cal
That 76.1 is without the anti brick buffer, but with the 4kWh zero mile buffer. That is to say, if you drive the car to zero mile, that "Remain" should be 4kWh. However, the figure may be reduced as the battery degrade. There is a Kman's video showing 2.5kWh left at zero mile. If that is also the case, then the estimated miles should be (76.1-2.5)/0.3=245.3, same as the TeslaFi's.
View attachment 286338

This is not correct. 2.5 kWh is the nominal energy remaining. This is available to the owner. The 4.0 kWh bricking buffer is not included in this value, and is unavailable to the driver.
 

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
Another odd thing is that if you divide the kWh discharge by the odometer, it comes out to 418 wh / mile but my life time average is 317.
 

lymex2018

Member
Feb 4, 2018
132
145
China
This is not correct. 2.5 kWh is the nominal energy remaining. This is available to the owner. The 4.0 kWh bricking buffer is not included in this value, and is unavailable to the driver.
All these are basically correct except "This is not correct". Beacuse we are saying the samething.
Only that the 2.5kWh is not counted for range display on the dash, it is part of the below zero buffer, and is usable to the user when you drive below zero mile like Kman did.
 

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
All these are basically correct except "This is not correct". Beacuse we are saying the samething.
Only that the 2.5kWh is not counted for range display on the dash, it is part of the below zero buffer, and is usable to the user when you drive below zero mile like Kman did.

There is no below zero mile buffer or zero mile buffer. That was dis-proven in the thread I quoted and many others.
 

lymex2018

Member
Feb 4, 2018
132
145
China
There is no below zero mile buffer or zero mile buffer. That was dis-proven in the thread I quoted and many others.
Then they are wrong.

I've given two examples above proofing that the below zero buffer exists. Your puzzle in this thread is just because of the exclusion of the below zero buffer, and I added the buffer to explain the match perfectly.

It might because of Tesla's modification to the parameters that there was no below zero buffer before but there is now. You can find the evidence in Bjorn's video at 0:08:58 when the guy is talking about the changes.
 
Last edited:

sorka

Well-Known Member
Feb 28, 2015
7,707
5,729
Merced, CA
Then they are wrong.

I've given two examples above proofing that the below zero buffer exists. Your puzzle in this thread is just because of the exclusion of the below zero buffer, and I added the buffer to explain the match perfectly.

It might because of Tesla's modification to the parameters that there was no below zero buffer before but there is now. You can find the evidence in Bjorn's video at 0:18:19 when the guy is talking about the changes.

I watched the video and I didn't interpret any of it as evidence that there is a zero mile buffer. The battery is physically maximum 81 kWh and 4 kWh is the anti bricking buffer leaving a maximum of 77 kWh left usable for driving. There is FAR more evidence in the thread I posted against there being a zero mile buffer.
 

lymex2018

Member
Feb 4, 2018
132
145
China
I watched the video and I didn't interpret any of it as evidence that there is a zero mile buffer. The battery is physically maximum 81 kWh and 4 kWh is the anti bricking buffer leaving a maximum of 77 kWh left usable for driving. There is FAR more evidence in the thread I posted against there being a zero mile buffer.
I didn't refer that video as the proof of the existence of the zero mile buffer, I referred it as there was software changes, which again answered the question in your first post here.

However, the video did proof that the zero mile buffer exist after the change, because when the dash display zero, the SOC UI is not.
 

apacheguy

S Sig #255
Oct 21, 2012
5,076
1,238
So Cal
All these are basically correct except "This is not correct". Beacuse we are saying the samething.
Only that the 2.5kWh is not counted for range display on the dash, it is part of the below zero buffer, and is usable to the user when you drive below zero mile like Kman did.

Not all vehicles have a below zero mile buffer. And it certainly isn’t the same on all vehicles. Another S60 could very well only show 1 kWh remaining at 0 miles. Another could show 0 kWh at 0 miles.
 

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