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

[AAKEE]

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

Only thing thats regulated is the EPA certification/sticker on the car.

What they display as range is free.

 

[PianoAl]

Tessie (see sig) 1.3 years old, has 6,225 miles and range at 100% is 262 (vs 273 originally. 4% degradation).

We usually charge to 75%, rarely to 100%.

 

[Owner4523]

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.


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.)

I'm going to take our kids on a camping trip over Spring Break and leave my house with a 100 charge. My app says I'll get to the camp ground with a 62% charge, and back home the day after at 35%. Any harm in letting the car stay at 62% for 24-48 hours (if we stay two nights?) I also like having the buffer in case we need to go somewhere outside of the camp ground. I could find a way to make it work with a lower state of charge overnight, but it would be more convenient if I did the 100% charge and let it last a few days. (I think these some of these threads have and me a little worried about letting my car sit for a day or two at anything higher than 55%.

 

[AlanSubie4Life]

I'm going to take our kids on a camping trip over Spring Break and leave my house with a 100 charge. My app says I'll get to the camp ground with a 62% charge, and back home the day after at 35%. Any harm in letting the car stay at 62% for 24-48 hours (if we stay two nights?) I also like having the buffer in case we need to go somewhere outside of the camp ground. I could find a way to make it work with a lower state of charge overnight, but it would be more convenient if I did the 100% charge and let it last a few days. (I think these some of these threads have and me a little worried about letting my car sit for a day or two at anything higher than 55%.

It’s fine. Charge to 100%.

 

[Owner4523]

It’s fine. Charge to 100%.

Thanks!

 

[DrGriz]

I'm going to take our kids on a camping trip over Spring Break and leave my house with a 100 charge. My app says I'll get to the camp ground with a 62% charge, and back home the day after at 35%. Any harm in letting the car stay at 62% for 24-48 hours (if we stay two nights?) I also like having the buffer in case we need to go somewhere outside of the camp ground. I could find a way to make it work with a lower state of charge overnight, but it would be more convenient if I did the 100% charge and let it last a few days. (I think these some of these threads have and me a little worried about letting my car sit for a day or two at anything higher than 55%.

I would be sure to turn off sentry mode and cabin overheat protection to maintain your buffer a little bit more.
Also, don't worry about the car sitting above 55% for a couple of days. It's average over time.

 

[Owner4523]

I would be sure to turn off sentry mode and cabin overheat protection to maintain your buffer a little bit more.
Also, don't worry about the car sitting above 55% for a couple of days. It's average over time.

Thanks. Over 30% seems like a big buffer though!

 

[DrGriz]

Thanks. Over 30% seems like a big buffer though!

Just saying, if you are concerned. Sentry mode and cabin overheat protection do add up. If you aren't worried then have at it.

 

[Owner4523]

Just saying, if you are concerned. Sentry mode and cabin overheat protection do add up. If you aren't worried then have at it.

Thanks, I was more concerned with charging to 100% and letting the car air at >60% until tomorrow when we come home. I normally charge only to 50% every night and it's typically airs lower than that overnight until it starts charging early in the am.

 

[DrGriz]

Thanks, I was more concerned with charging to 100% and letting the car air at >60% until tomorrow when we come home. I normally charge only to 50% every night and it's typically airs lower than that overnight until it starts charging early in the am.

Gotcha. One or two days will make no measurable difference. Calendar aging is a long term prospect.

 

[Bouba]

With an electric car you can geek out on it...or treat it like a car. But even geeks have to treat it like a car when they go on a road trip

 

[nicksp]

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)

As per fueleconomy.gov the range of my 18 M3LR is 310 miles but the experts here insist I use 325 for any baseline calculations.

 

[navguy12]

As per fueleconomy.gov the range of my 18 M3LR is 310 miles but the experts here insist I use 325 for any baseline calculations.

I also have a May 2018 build TM3 that arrived with a range of 499 km…and that was the maximum range that car showed at 100% SOC until it started to show loss of range about 18 months ago (currently 100% will show ~480 km).

 

[AlanSubie4Life]

As per fueleconomy.gov the range of my 18 M3LR is 310 miles but the experts here insist I use 325 for any baseline calculations.

Yes. That is close to correct, it is one of the exceptions mentioned. The only one I can think of, though I know 2020 Ps were delivered with 310 before an update to 299, which is an exception, and different than the 2018, and probably not something Tesla would want to repeat.

Notably, for your car, the EPA test produced around 330 miles (look it up on the EPA data file spreadsheet), but was voluntarily reduced to 310. So 325 was just going back to close to the actual rating.

And actually as you might expect, you should start with 332 miles for your calculations. That’s correct, of course, since 234Wh/mi *332mi = 77.8kWh. Also aligns quite closely with EPA.

 

[Quickst]

Apologies @AAKEE do you know the article link for this

 

[AAKEE]

Apologies @AAKEE do you know the article link for thisView attachment 1028192

Of course: Link

Thread here about this and another report:

Link

 

[Quickst]

Thank you @AAKEE

 

[navguy12]

Nice slow trickle top up charge prior to leaving on a road trip last Friday.

Best the car ever showed was 499 km at 100% SOC.

Five years and 10 months old; 121,000 km.

 

[Hiline]

Just found this video where the Chief Engineer of Tesla claimed that their latest nickle-based batteries lose only 5%-6% of capacity after 10 years:

 

[Bouba]

Just found this video where the Chief Engineer of Tesla claimed that their latest nickle-based batteries lose only 5%-6% of capacity after 10 years:

I have watched so many of these videos and read so many reviews....you would think I would be desensitized by now...instead I just really want one