A senior tesla executive's comforting answer to concerns re: "loss of range"

[Doug_G]

Possibly even smaller factors: radio volume, which apps you leave open (I could see displaying the camera using more), which radio source you are using, brightness/night mode, seat heaters, kids seats (weight), stop and go traffic vs highway, speed, total passenger weight, regen. Some aren't much, but it all adds up.

Most of the stuff you mention is really pretty meaningless in terms of power draw. Let's say playing the radio loud takes 40W. Driving at modest highway speed takes 25 kW. You're talking about something almost a thousandth of the drive train power as if it matters. It doesn't, unless you're worried about falling feet short of your destination. Slowing down 1 mph will have massively more impact.

The two things that really matter are speed and cabin heater use.

 

[Kraken]

Most of the stuff you mention is really pretty meaningless in terms of power draw. Let's say playing the radio loud takes 40W. Driving at modest highway speed takes 25 kW. You're talking about something almost a thousandth of the drive train power as if it matters. It doesn't, unless you're worried about falling feet short of your destination. Slowing down 1 mph will have massively more impact.

The two things that really matter are speed and cabin heater use.

I said they were all minor, but they all add up. Most car audio amplifiers range between 120-1200W... So it isn't completely negligible. Even 500w would be 2%.

 

[ElSupreme]

I said they were all minor, but they all add up. Most car audio amplifiers range between 120-1200W... So it isn't completely negligible. Even 500w would be 2%.

Amps are sized based on instantaneous draw. Even a 1200W amp isn't going to put out 500W continuous. I bet a blasting stereo at 11 doesn't pull more than 200W average over the length of a song.

Besides running the stereo that loud basically necessitates rolling down the windows, which will probably cause way more than 200W of drag.

 

[Schmo]

Blimey! Enough flannel already! Can someone who has an S with apparent range reduction *please* just go out and see if they can do 20, 30, 40 miles or whatever past zero and prove Mr Guillen's theory is correct… or not? Thank you!

A month ago I took the family on a road trip in my 60. I hit zero much earlier than I expected. I turned on range mode, turned off the HVAC, and started driving slow. To my surprise, I was able to go almost 40 miles with "Charge Now" on the dash before reaching my destination.

 

[Doug_G]

I said they were all minor, but they all add up. Most car audio amplifiers range between 120-1200W... So it isn't completely negligible. Even 500w would be 2%.

Uh, no. That's peak output. Average output would be pretty darn small. We're talking a fraction of a percent for any reasonable sound output level.

 

[Kraken]

Uh, no. That's peak output. Average output would be pretty darn small. We're talking a fraction of a percent for any reasonable sound output level.

I understand that, I worked in audio... I wasn't just talking about the sound. I was saying there was enough other factors that can add up. Clearly it isn't huge, but probably noticeable.

 

[bluetinc]

Please post the other links if you can, I'm always up for some good reading!

Peter

As an EE, I have always assumed some method of coulomb counting was going on since voltage methods are difficult with Li-ion. This article is worth a read:

Hearst Article

I have some IEEE related links I can post but they get pretty technical.

 

[Kipernicus]

A month ago I took the family on a road trip in my 60. I hit zero much earlier than I expected. I turned on range mode, turned off the HVAC, and started driving slow. To my surprise, I was able to go almost 40 miles with "Charge Now" on the dash before reaching my destination.

Wow that's living on the edge. I think with version 5.9 you won't be able to do that.

 

[Jason S]

Proper tire inflation, air suspension or not, battery pack type, firmware, bad alignment, etc.


for all we know the main culprit here is that some peoples tires aren't properly inflated. Their car is using more energy per mile and the algorithm is thus getting confused.

After driving a bit on Oregon highways, I'm thinking the road condition matters too. Those Oregon roads were ROUGH; tons of pitting and road noise.

Edit: ... which, of course, jerry33 mentioned in his list:
Alignment
Tire type
Tire pressures
Road surface
Weather and Temperature
Traffic
Driving style
Terrain
Practice (a lot of practice)

 

[VolkerP]

A month ago I took the family on a road trip in my 60. I hit zero much earlier than I expected. I turned on range mode, turned off the HVAC, and started driving slow. To my surprise, I was able to go almost 40 miles with "Charge Now" on the dash before reaching my destination.

An empty Tesla S-60 goes further than a fully charged Chevy Volt :tongue:

 

[bluetinc]

On the 5.9, at the point at which the range is 0, the battery is truly in exactly the same state as it was in 5.8 (and before). That hasn't changed since I've had my car (4.0).

Peter

Wow that's living on the edge. I think with version 5.9 you won't be able to do that.

 

[Cottonwood]

On the 5.9, at the point at which the range is 0, the battery is truly in exactly the same state as it was in 5.8 (and before). That hasn't changed since I've had my car (4.0).

Has anyone actually taken a 5.9 car "below 0" to verify that this is just a change in how the battery indicator is displayed for 0 rated miles and "charge now"?

 

[qwk]

On the 5.9, at the point at which the range is 0, the battery is truly in exactly the same state as it was in 5.8 (and before). That hasn't changed since I've had my car (4.0).

Peter

This is false. Tesla shifted the rated range, but the battery bar vs. voltage has remained the same. Zero miles is definately not the same battery voltage from FW 4.2 to 5.0+.

 

[bluetinc]

Do you have any proof of this? I have actual data I have taken since 4.0 on my car that shows it has not moved at all, other than a small (<1.5 miles) adjustment that may or may not have been there when it is very cold out that I had to retest with warmer weather.

This is false. Tesla shifted the rated range, but the battery bar vs. voltage has remained the same. Zero miles is definately not the same battery voltage from FW 4.2 to 5.0+.

- - - Updated - - -

My reference point is that actual battery pack voltage at 0 not the displays on the battery indicator. I have not taken my car much into the "Charge now" area, so I can't say that they haven't changed the actual reserve they allow one to use.

Has anyone actually taken a 5.9 car "below 0" to verify that this is just a change in how the battery indicator is displayed for 0 rated miles and "charge now"?

 

[qwk]

Do you have any proof of this? I have actual data I have taken since 4.0 on my car that shows it has not moved at all, other than a small (<1.5 miles) adjustment that may or may not have been there when it is very cold out that I had to retest with warmer weather.

Look at the pics below. The first one is FW 3.X, the second is somewhere in the 5.X. The battery bar has always stayed the same vs. voltage. Tesla has never(even the roadster) let the cells charge over ~95%, and there is also a small buffer in the lower rage to prevent bricking. The only thing that has shifted is the rated range.

In addition to the above, Jerome also stated that there is an upcoming FW change to address the issue of "range drift", for those who only use a small percentage of their pack, which throws the estimation of rated range left. Most people don't have the degradation issue that you speak of. It's just one of the many factors that skew the numbers shown.

- - - Updated - - -

I hope YoBigD doesn't mind me reposting his pic.

 

[bluetinc]

I'm afraid that you are false drawing conclusions from something that isn't real. The time at which the display shows a red battery changes due to temperature (and posibbly other things) and doesn't really represent anything in itself. I have had my battery bar show both yellow and red, and at both times the SOC from VT was shown as the same and MUCH more importantly the battery pack voltage was the same, 316 V. You really can't compare a visual display representative of the battery with actual Voltage. As all my statements have clearly specified that the software versions that I can compare are from 4.0+, so if you are really dipping back to 3.X, you are placing words in my mouth that I never stated.

Perhaps we can talk real data and measurements rather than pointing at Jeromes future statements that seem to be more management PR and damage control than fact. Speaking for my car, I have real numbers of useable capacity of my battery dropping by 10% now, 80kWh -> 72kWh. I don't care what the range says, if it's correct, or incorrect, the actual amount of useable energy my battery can provide has dropped by 10% at the same pack voltage points.

I am by far not the only person seeing this. But, I agree that most people don't have the same degradation that I do, and all those seem to have B packs..... If you feel that my degradation is skewing my numbers, please elaborate on how this is and how we would be able to determine it.

Look at the pics below. The first one is FW 3.X, the second is somewhere in the 5.X. The battery bar has always stayed the same vs. voltage. Tesla has never(even the roadster) let the cells charge over ~95%, and there is also a small buffer in the lower rage to prevent bricking. The only thing that has shifted is the rated range.

In addition to the above, Jerome also stated that there is an upcoming FW change to address the issue of "range drift", for those who only use a small percentage of their pack, which throws the estimation of rated range left. Most people don't have the degradation issue that you speak of. It's just one of the many factors that skew the numbers shown.

 

[qwk]

I'm afraid that you are false drawing conclusions from something that isn't real. The time at which the display shows a red battery changes due to temperature (and posibbly other things) and doesn't really represent anything in itself. I have had my battery bar show both yellow and red, and at both times the SOC from VT was shown as the same and MUCH more importantly the battery pack voltage was the same, 316 V. You really can't compare a visual display representative of the battery with actual Voltage. As all my statements have clearly specified that the software versions that I can compare are from 4.0+, so if you are really dipping back to 3.X, you are placing words in my mouth that I never stated.

Perhaps we can talk real data and measurements rather than pointing at Jeromes future statements that seem to be more management PR and damage control than fact. Speaking for my car, I have real numbers of useable capacity of my battery dropping by 10% now, 80kWh -> 72kWh. I don't care what the range says, if it's correct, or incorrect, the actual amount of useable energy my battery can provide has dropped by 10% at the same pack voltage points.

I am by far not the only person seeing this. But, I agree that most people don't have the same degradation that I do, and all those seem to have B packs..... If you feel that my degradation is skewing my numbers, please elaborate on how this is and how we would be able to determine it.

You are assuming too much. I wasn't going off of the color of the bar(which does vary due to conditions). The bar clearly changes in small segments, which translate into battery percentage(note that this isn't true battery percentage, but Tesla's usable parameters). I can dig up more of these pics if you are still stuck on this(which span all different FW versions). The two pics clearly show two different states of charge at the same rated range. You cannot change this fact. The bar moves every 1-2%.

How exactly are you measuring battery voltage? A multimeter measurement at the pack is useless because not every module has the same voltage as the entire pack. Since rated range takes this into account, your conclusions are nearly useless. I'm basing mine off of the few times I have seen the battery management screen, which tells you exactly how Tesla's rated range changes were implemented.

For some reason you are trying to prove battery degradation, which in most cases simply isn't there.

 

[bluetinc]

It sounds like you are determined to be correct regardless of data or discussion. Perhaps you would like to share this insight into the BMS showing you the changes that Tesla has made? But, instead of this, you respond with uncertainty and doubt and a vague assertion that you know more than you are letting on.

I find it totally baffling that you propose to use a software generated graphic line to show the 0 range point, rather that an actual battery pack voltage. (note this is what we started with, not a degradation discussion). Further you go on to state that a pack voltage is useless? Perhaps you don't realize that the pack voltage is all those small cells stacked up on each other?

Lets just call this quits as it's clear that you are determined to say that degradation is not happening and discount any discussion that might conflict with that.

Peter

You are assuming too much. I wasn't going off of the color of the bar(which does vary due to conditions). The bar clearly changes in small segments, which translate into battery percentage(note that this isn't true battery percentage, but Tesla's usable parameters). I can dig up more of these pics if you are still stuck on this(which span all different FW versions). The two pics clearly show two different states of charge at the same rated range. You cannot change this fact. The bar moves every 1-2%.

How exactly are you measuring battery voltage? A multimeter measurement at the pack is useless because not every module has the same voltage as the entire pack. Since rated range takes this into account, your conclusions are nearly useless. I'm basing mine off of the few times I have seen the battery management screen, which tells you exactly how Tesla's rated range changes were implemented.

For some reason you are trying to prove battery degradation, which in most cases simply isn't there.

 

[qwk]

It sounds like you are determined to be correct regardless of data or discussion. Perhaps you would like to share this insight into the BMS showing you the changes that Tesla has made? But, instead of this, you respond with uncertainty and doubt and a vague assertion that you know more than you are letting on.

I find it totally baffling that you propose to use a software generated graphic line to show the 0 range point, rather that an actual battery pack voltage. (note this is what we started with, not a degradation discussion). Further you go on to state that a pack voltage is useless? Perhaps you don't realize that the pack voltage is all those small cells stacked up on each other?

Lets just call this quits as it's clear that you are determined to say that degradation is not happening and discount any discussion that might conflict with that.

Peter

I'm not determined to be correct. I am, otherwise I wouldn't post incorrect info. Do I have the ability to post pics of the BMS screen, no. I do care about accurate data, therefore I try to correct posts that are simply inaccurate.

You claim to know sophisticated battery systems, yet fail to get the basic things correct. In order to a sense of what Tesla is doing with the software changes, one needs very precise information. Rated range or any battery capacity info for that matter is very sensitive to information inputs. If one just gets a rough idea of what the numbers are, there is no way to come up with anything that is for sure.

Please go look at the different battery percentage pics for different firmwares all over the web with zero rated miles left. There is an indisputable difference of battery capacity left. When you couple that with the fact that with the early firmwares the car stopped just under zero rated, and later firmwares allowed the car to travel 15-10 miles after zero, this alone proves that the rated range was merely shifted, and the battery bar was left alone. These two facts debunk your entire conclusion without even taking battery voltage into account.