Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[AAKEE]

Hello, my support chat with Tesla service questioning range stated:

Model Y performance fall 2022, model year 2023 to now, meaning Jan/Feb/Mar 2024, orig range is 285 miles

EPA = 303 miles.
The cars did show 487km/303 mi new.

Model Y LR fall 2022, model year 2023 to now, orig range is 310 miles

Doesnt match my memory numbers, EPA was 330 mi from 2022 when they started using the 2170L 82.1 kWh pack.

Displayed range = 330 miles down to ~ 79 kWh capacity.

Model year 2022, 2021 are not affected
Does not make sense as the only range significant difference is the heat pump between years 2021 to now.

My range loss after 15 month, 13K miles is 1.4% with 80% charged nightly, 95% for long road trips, 100% monthly/bimonthly rebalancing

If you charge to 80% nightly, you probably have lost ~ 6% to calendar aging. Depends on where you live (how warm the climate is etc.)

I would guess the car shows about ~ 287 miles now, and that is a 6% loss from the 81 kWh delivered in the EPA test.

 

[AlanSubie4Life]

Hello, my support chat with Tesla service questioning range stated:

Model Y performance fall 2022, model year 2023 to now, meaning Jan/Feb/Mar 2024, orig range is 285 miles

Model Y LR fall 2022, model year 2023 to now, orig range is 310 miles

Model year 2022, 2021 are not affected
Does not make sense as the only range significant difference is the heat pump between years 2021 to now.

My range loss after 15 month, 13K miles is 1.4% with 80% charged nightly, 95% for long road trips, 100% monthly/bimonthly rebalancing

I am not sure what this post means.

Anyway, prior models will not be affected by EPA adjustments, regardless of what Tesla support chat may say. They’re probably just using an AI bot to answer questions anyway. Accuracy will likely be similar.

As @AAKEE says, just use fueleconomy.gov to look up original range of your vehicle. That is your starting point and it won’t change (minor irrelevant caveats above)

 

[DrChaos]

Hello, my support chat with Tesla service questioning range stated:

Model Y performance fall 2022, model year 2023 to now, meaning Jan/Feb/Mar 2024, orig range is 285 miles

Model Y LR fall 2022, model year 2023 to now, orig range is 310 miles

Model year 2022, 2021 are not affected
Does not make sense as the only range significant difference is the heat pump between years 2021 to now.

The change is regulatory not technological. EPA decided that reported range/efficiency must be average of best and worst modes, not a default.

 

[AlanSubie4Life]

The change is regulatory not technological. EPA decided that reported range/efficiency must be average of best and worst modes, not a default.

And the changes are not retroactive. There is verbiage in the order that confuses people, but it only applies to new testing of old vehicles (no idea when/how that might occur).

Vehicles sold with a given range will continue to have that range with an undegraded pack. New vehicles (e.g. 2024 Model Y LR AWD) may show adjustments (Shows 303 with current factory firmware with ~79.5kWh degradation threshold and minimum capacity; sold with 310 miles, will adjust at some point to match that number. First software update did not do that. Maybe the next one.)

 

[Bouba]

And the changes are not retroactive. There is verbiage in the order that confuses people, but it only applies to new testing of old vehicles (no idea when/how that might occur).

Vehicles sold with a given range will continue to have that range with an undegraded pack. New vehicles (e.g. 2024 Model Y LR AWD) may show adjustments (Shows 303 with current factory firmware with ~79.5kWh degradation threshold and minimum capacity; sold with 310 miles, will adjust at some point to match that number. First software update did not do that. Maybe the next one.)

It’s going to be hard to explain to a newcomer why a second hand Tesla has a longer range than a new one. We all know that it’s just fiddling the numbers...but numbers do matter.
Perhaps as the battery degrades, Tesla can keep raising the displayed range until degradation exceeds the EPA....and make it a numeric buffer

 

[Owner4523]

Damn...I have been trying to keep it at %60...

In addition to @AlanSubie4Life very good post:

You might wanna read some of the posts here on TMC written by me or others about research data for calendar aging and keeping the SOC below 55% most of the time.

I had the same pack but a higher degradation threshold, I did’nt loose any range until 39K km and ~ 1.5 years.

Some of the things Jeff says doesnt match the other research in detail. I do not question if he knows. He should know but he might be locked in for what to tell us from the earlier work togehter with Tesla or just is protecting himself from possible missunderstandings cousing people to sue him or something like that?
(Also, he seldom seems to make advices aimed for a certain chemistry)

You would like to stay below 55% most of the time.

- Do not charge more than needed until next charge.
-Charge often (reduces the need per above point)
-Charge late - reduces time at high SOC.




Earlier there was a lot of talk about ”battery lottery” here on TMC.
I do not really believe that. Battery degradation is very predictable.

Your strategy makes a difference.

"Some of the things Jeff says doesnt match the other research in detail." // Can you share more detail where what he shares is different from other research? I feel like people really hang their hat on the things he says in that one video on YouTube.

 

[AAKEE]

"Some of the things Jeff says doesnt match the other research in detail." // Can you share more detail where what he shares is different from other research? I feel like people really hang their hat on the things he says in that one video on YouTube.

Well, if you look at what I guess is one of his latest videos it matches the research reports quite well.

In the most common videos that people link to he recommends 70% as the best SOC to charge to, and the common talk is circling around cycles and no talk about Calendar aging which is very strange.
I do not remember all details, I saw the older videos a few years back when people had objections about the research reports I posted data from pointing to he’s videos. He’s explanations has always been on a very technical level but from my point of view there are important things he never discussed and also sone things that did not match the research result.
There is a possibility that he either was prohibited by contract (Tesla cooperstion) to tell people to use low SOC, or that he might see 70% as the optimum compromixe between range and relative degradation.
He knows off course, but I was not really able to connect he’s statement with the research.

 

[Owner4523]

Well, if you look at what I guess is one of his latest videos it matches the research reports quite well.

In the most common videos that people link to he recommends 70% as the best SOC to charge to, and the common talk is circling around cycles and no talk about Calendar aging which is very strange.
I do not remember all details, I saw the older videos a few years back when people had objections about the research reports I posted data from pointing to he’s videos. He’s explanations has always been on a very technical level but from my point of view there are important things he never discussed and also sone things that did not match the research result.
There is a possibility that he either was prohibited by contract (Tesla cooperstion) to tell people to use low SOC, or that he might see 70% as the optimum compromixe between range and relative degradation.
He knows off course, but I was not really able to connect he’s statement with the research.

Thanks. I know people like to use one of his videos to talk about how you shouldn't charge to 100% to avoid micro cracking. I also recently heard someone say that Jeff suggest it's better to discharge from a higher level instead of a lower one. (ie: it's better to go from 80%-50% than from 50%-20%.) Based on what I've learned from you, it's better to go from lower to lower.

 

[AAKEE]

Thanks. I know people like to use one of his videos to talk about how you shouldn't charge to 100% to avoid micro cracking. I also recently heard someone say that Jeff suggest it's better to discharge from a higher level instead of a lower one. (ie: it's better to go from 80%-50% than from 50%-20%.) Based on what I've learned from you, it's better to go from lower to lower.

The enormous amount of research data agrees on quite much so where 100 research reports comes to the same conclusions or have similar test result I guess this is worth quite much.

It it possible to find slight (not big but anyway) deviations if you only read research reports from one person or group.

I try to use as wide amount of reports as possible so the possible faulty findings from one person/group do not affect the sum of the reports read.

In the Jeff Case, I respect him and I think he knows very much. But he is a single source and when there is deviations feom the sum of all research I go by that.
Several people here seem to only have seen hes videos and has taken those as the 100% truth.
It is also interresting that he somehow changed the approach in the new video compared to before.
There are threads here where these things are discussed. Do a search, I have been in a few of these threads.

 

[CyberGus]

Several people here seem to only have seen hes videos and has taken those as the 100% truth.

I never charge my truth to 100%

 

[johnny_cakes]

In the Jeff Case, I respect him and I think he knows very much. But he is a single source and when there is deviations feom the sum of all research I go by that.
Several people here seem to only have seen hes videos and has taken those as the 100% truth.
It is also interresting that he somehow changed the approach in the new video compared to before.
There are threads here where these things are discussed. Do a search, I have been in a few of these threads.

@Owner4523
Jeff Dahn's words verbatim from here:

"The lower the state of charge, the better, right? But 75% is a pretty good number [Ed: in case you need it]."

 

[Owner4523]

@Owner4523
Jeff Dahn's words verbatim from here:

"The lower the state of charge, the better, right? But 75% is a pretty good number [Ed: in case you need it]."

?

 

[Bouba]

My car is permanently at 49%.....it doesn’t like 50% (although at one time it liked 51%).....for a road trip I put more...including 100% if it is a long trip

 

[AAKEE]

@Owner4523
Jeff Dahn's words verbatim from here:

"The lower the state of charge, the better, right? But 75% is a pretty good number [Ed: in case you need it]."

In that case, a well placed ”as 75% causes quite much calendar aging it could be wise to charge just before the trip”

And:

”All other days you might go lower”

Many have objected against ”the lower the better” with referense to his vid’s.
They might have missunderstood Jeffs videos though.
(I looked at several, about three year back when I joined TMC, but I do not remeber everything from there)

 

[johnny_cakes]

?

Just confirmation from Jeff Dahn that "lower the state of charge, the better", which is consistent with @AAKEE's research reports. His suggestion to charge more is for convenience and practicality (per video linked to above).

 

[ran349]

And the changes are not retroactive. There is verbiage in the order that confuses people, but it only applies to new testing of old vehicles (no idea when/how that might occur).

Vehicles sold with a given range will continue to have that range with an undegraded pack. New vehicles (e.g. 2024 Model Y LR AWD) may show adjustments (Shows 303 with current factory firmware with ~79.5kWh degradation threshold and minimum capacity; sold with 310 miles, will adjust at some point to match that number. First software update did not do that. Maybe the next one.)

It's not just the 2024 model Y that is showing less than the "advertised" EPA estimate. People are claiming that the 2024 Model S Plaid is showing only 347 miles at 100% charge with an advertised range estimate of 359 miles.

When Tesla was asked about this they said "it is normal to lose range in the first few months". They say this to people that have brand new cars and have seen no degradation at all.

I believe Tesla is just responding to all the complaints about their cars not achieving the advertised range and just setting the numbers even lower than the new advertised ratings, which were already adjusted downward.

Tesla can set the range lower but not higher than the EPA rating. Of course, they should be upfront about that with their customers instead of calling it normal degradation. I think it is pretty sneaky on Tesla's part, but so is including the buffer in the rated range calculation but not in the 100% to 0% SOC range.

I guess I am saying I don't think it is a mistake by Tesla but actually intentional. But we will see if they ever adjust anything going forward.

 

[3sr+buyer]

It's not just the 2024 model Y that is showing less than the "advertised" EPA estimate. People are claiming that the 2024 Model S Plaid is showing only 347 miles at 100% charge with an advertised range estimate of 359 miles.

This is not mixing up estimates with different wheels and tires, right?

Anyway, Tesla has done this in other countries, where they have to quote the highly optimistic WLTP range, but use US EPA or similar in their rated remaining range display.

 

[AAKEE]

It's not just the 2024 model Y that is showing less than the "advertised" EPA estimate. People are claiming that the 2024 Model S Plaid is showing only 347 miles at 100% charge with an advertised range estimate of 359 miles.

This is not mixing up estimates with different wheels and tires, right?

Anyway, Tesla has done this in other countries, where they have to quote the highly optimistic WLTP range, but use US EPA or similar in their rated remaining range display.

They have not change the displayed range in ”WLTP-land”.

2023 and before S Plaid is 348mi/560 km with the 21” arachnid. 396mi / 637 km with the 19”. And they still is, in WLTP-land.

This is my Plaid, in Sweden/WLTP-land.
Still showing 560km on every full charge.
Teslafi gets rounded percent which probably is the reason for varying a lot and mostly showing 5-7km lower max range that the real max range.

The peak early in the chart was me testing to change to the 19” wheels. Everything else in the chart is 21” arachnid(Plaid).

It seems common by Tesla users to find own solutions that *mentally hides* degradation. (Not at all meaning you, but that there is statements that comes from sources with no facts, just assumed things.)

Tesla displays the range the car was EPA cerified, this is not changed backwards.
As @AlanSubie4Life wrote, a new version can need an update to display the certified range.

My M3P 21 which was an early refresh showed 499km the first month or so, until they fixed the 315 mi/ 507 km EPA range.

 

[AlanSubie4Life]

I guess I am saying I don't think it is a mistake by Tesla but actually intentional. But we will see if they ever adjust anything going forward

They’ve done updates in the past which increase range in the first few months. So there is hope. But you could be right! (And I am not claiming it is a mistake - they deliberately biased low for reasons stated not having exact final number in hand at the time.)

Anyway:
Yes, a lower number of miles on the dash will help keep real world results more in line with what is on the dash. Though people presumably are thinking about the EPA number they were sold, not the number on the dash, when they look at achieved range. But who knows.

Tesla can set the range lower but not higher than the EPA rating.

Not quite. AFAIK: They can, on the EPA sticker, put a lower number for the range than the test results give (voluntary reduction). But they still have to provide the test-measured charge-depletion energy regardless of any such adjustments (there may be a small allowed tolerance on energy, but that is not relevant here).

Of course, they are allowed to set the range display (something totally different) in the car to whatever they want (what they are doing here). They could put 1000 miles on the range display, much higher than the window sticker. All that matters is the window sticker value for range and the energy, I think. Of course, for Tesla, it is customary to have some alignment of sticker and displayed value (this is great). Rather than a guessometer or whatever.

Anyway we’ll see if they make the adjustment. They may not. This number is arbitrary, and funny business is possible as you say.

We know they aren't just lowering the degradation threshold (this is a potential hypothesis - starting with a much lower range but the same (correct) constant would allow hiding a lot of battery degradation), because the energy screen still calculates out to 79.5kWh for these vehicles. And that method does not reveal energy in excess of the threshold. So the constant for 2024 Model Y LR AWD is around 79.5kWh/303 miles = 262Wh/mi. (Just roughly; I don't have the vehicle so exact numbers tough to get.)

 

[ran349]

Tesla can set the range lower but not higher than the EPA rating.

Not quite. AFAIK: They can, on the EPA sticker, put a lower number for the range than the test results give (voluntary reduction). But they still have to provide the test-measured charge-depletion energy regardless of any such adjustments (there may be a small allowed tolerance on energy, but that is not relevant here).

Of course, they are allowed to set the range display (something totally different) in the car to whatever they want (what they are doing here). They could put 1000 miles on the range display, much higher than the window sticker. All that matters is the window sticker value for range and the energy, I think. Of course, for Tesla, it is customary to have some alignment of sticker and displayed value (this is great). Rather than a guessometer or whatever.

I agree with you here. I should have been more precise and said they can adjust the displayed range.