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

[hcdavis3]

As many of you know, my 2018 LR-AWD has always shown approx. 310 miles since I got it in Dec 2018, mfr'd Oct 2018. Here's today's Stats chart:
View attachment 718838
Up until about 15k miles, the chart shows seasonality, since the Stats developer was using the SOC api that didn't factor temps. I think it was January of this year, when he finally switched to the other SOC api that did factor in temps, so you no longer have the seasonality swings due to temps. So, from 15k onward, I've been pretty much flat on 310 miles of estimated range.

Not sure why there seems little to no aging; presumably the deg is so slow it hasn't used up the top buffer yet.

Looks like you have a really good battery. I’m hoping mine will be the same. So far so good.

TeslaFi.com Tesla Model S 3 X Y Data Logger

 

[Macb00kemdanno]

I have a quick question. I have a SR+ with 1300 miles on the odometer (took deliver in August; this is not an LFP car). I only charge to between 80 to 90 percent, but tomorrow I’m getting ready to take my first long distance trip so I just plugged it in to the Tesla Wall Connector in the garage. I pushed the slider to 100% for the first time and the app is showing a max of between 253 to 257 miles instead of 263. Is that normal?

 

[AlanSubie4Life]

Is that normal?

Yes. Time will tell what your pack actually gets to. The accuracy of that extrapolation also depends on what is your current SOC (the higher the SOC, the better the extrapolation).

Your current NFP is approximately (your 100% charge in miles) / 263 miles * 53.5kWh. You likely started with something around 53.5kWh.

Enjoy the trip.

 

[Macb00kemdanno]

Yes. Time will tell what your pack actually gets to. The accuracy of that extrapolation also depends on what is your current SOC (the higher the SOC, the better the extrapolation).

Your current NFP is approximately (your 100% charge in miles) / 263 miles * 53.5kWh. You likely started with something around 53.5kWh.

Enjoy the trip.

Thanks!

 

[Candleflame]

I have a quick question. I have a SR+ with 1300 miles on the odometer (took deliver in August; this is not an LFP car). I only charge to between 80 to 90 percent, but tomorrow I’m getting ready to take my first long distance trip so I just plugged it in to the Tesla Wall Connector in the garage. I pushed the slider to 100% for the first time and the app is showing a max of between 253 to 257 miles instead of 263. Is that normal?

yes.

 

[Occar]

As many of you know, my 2018 LR-AWD has always shown approx. 310 miles since I got it in Dec 2018, mfr'd Oct 2018. Here's today's Stats chart:
View attachment 718838
Up until about 15k miles, the chart shows seasonality, since the Stats developer was using the SOC api that didn't factor temps. I think it was January of this year, when he finally switched to the other SOC api that did factor in temps, so you no longer have the seasonality swings due to temps. So, from 15k onward, I've been pretty much flat on 310 miles of estimated range.

Not sure why there seems little to no aging; presumably the deg is so slow it hasn't used up the top buffer yet.

This is in line with what I’ve always seen. Keep them 3 years. Keep them plugged in at 90% all the time. Little to no loss. I think my S lost 2 miles rated in that time. As I've always said, anyone telling you to do something else is just making your life harder.

it always seems to be the people who have weird charging habits that have the weird loss. Just do what the manufacturer says and ignore random internet experts.

 

[USCGDAV]

First post here, so hopefully I don't anger the mods.

On Sunday I bought my first Tesla, a used 2018 Long Range Model 3 with 24k miles on it. Last night I charged it to 100% for the first time and the estimated range is only 281 miles. I thought the Long Range was supposed to have a range of 353 miles? I know the range is supposed to decrease slightly over time but a 20% decrease in 3 years seems a lot. Is that expected or could it indicate something is wrong?

Same thing happened to me and mine won't charge beyond 272. If it goes down a lot further then schedule an at home service call. They'll run diagnostics and see if there's a problem. No problem then wait and see if the battery degradation gets worse. Remember they have to replace the battery under warranty, however, don't sweat it as the car you purchased was driven for a few years and they truly drove the car. Remember some people drive the car like it's a golf cart trying to squeeze out every mile watt they can while others (like me) don't care and drive it like it was a performance model

 

[KenC]

This is in line with what I’ve always seen. Keep them 3 years. Keep them plugged in at 90% all the time. Little to no loss. I think my S lost 2 miles rated in that time. As I've always said, anyone telling you to do something else is just making your life harder.

it always seems to be the people who have weird charging habits that have the weird loss. Just do what the manufacturer says and ignore random internet experts.

Yes, but I'm one of those people with "weird charging habits".

 

[Twiglett]

My BMS is have real fun figuring out what capacity my 2018 Model 3 (so RWD LR) has
Currently the calculated charge is 63kW which feels low for 46k miles
Tesla say the battery is fine and working as expect.

 

[AlanSubie4Life]

Currently the calculated charge is 63kW which feels low for 46k miles

So 269 miles out of 325 miles originally. Definitely worse than one would hope for. I’d believe the BMS though.

So 19% (or 17% depending on how you count) capacity loss.

 

[Hokiegirl112]

I have a 2019 model 3 performance with 17k miles. At 100% charging my battery degraded from 310 to 300. However, I had to get the 12v battery replaced and now it’s showing that at 100% I get a range of 280. Seems they replaced it with a worse battery reading the limited warrenty they can replace it with a reconditioned battery which they did. I assume since it’s stated in their warranty there’s nothing I can do and just have to deal with a big drop in range?

 

[Stellavator]

First post here, so hopefully I don't anger the mods.

On Sunday I bought my first Tesla, a used 2018 Long Range Model 3 with 24k miles on it. Last night I charged it to 100% for the first time and the estimated range is only 281 miles. I thought the Long Range was supposed to have a range of 353 miles? I know the range is supposed to decrease slightly over time but a 20% decrease in 3 years seems a lot. Is that expected or could it indicate something is wrong?

Your 2018 M3 never had a range of 353. It was 310 when new. The ranges bumped up on later builds. 281 miles estimate for 100% charge on a 2018 is very common, and right about where mine is too. There is nothing wrong with your car.

 

[AAKEE]

I have a 2019 model 3 performance with 17k miles. At 100% charging my battery degraded from 310 to 300. However, I had to get the 12v battery replaced and now it’s showing that at 100% I get a range of 280. Seems they replaced it with a worse battery reading the limited warrenty they can replace it with a reconditioned battery which they did. I assume since it’s stated in their warranty there’s nothing I can do and just have to deal with a big drop in range?

If you are sure they changed the 12V battery, that battery to 99.99% was a brand new battery.
The 12V battery does not have anything to do with range. The 12V battery is a small lead battery used for other stuff then delivering power to the wheels.
Maybe the BMS got reset when making the car powerless for the 12V swap?

 

[Hokiegirl112]

If you are sure they changed the 12V battery, that battery to 99.99% was a brand new battery.
The 12V battery does not have anything to do with range. The 12V battery is a small lead battery used for other stuff then delivering power to the wheels.
Maybe the BMS got reset when making the car powerless for the 12V swap?

That was very informative. Appreciate it.

 

[notsure11]

Your 2018 M3 never had a range of 353. It was 310 when new. The ranges bumped up on later builds. 281 miles estimate for 100% charge on a 2018 is very common, and right about where mine is too. There is nothing wrong with your car.

I also have 2018 M3 LR RWD, which was advertised as having 310 mile range. Just checked Tesla app and it’s showing 287 miles at 99%. (Or 230 miles at 79%). The car only has 8,700 miles and I’ve gone above 90% only a handful number of times. I plug it in every day and it’s set to charge to 80% (although I used to do 90%).

287 miles sounds low to me but I live on a hill so I don’t think I get a very good miles-per-watt.

 

[Candleflame]

I also have 2018 M3 LR RWD, which was advertised as having 310 mile range. Just checked Tesla app and it’s showing 287 miles at 99%. (Or 230 miles at 79%). The car only has 8,700 miles and I’ve gone above 90% only a handful number of times. I plug it in every day and it’s set to charge to 80% (although I used to do 90%).

287 miles sounds low to me but I live on a hill so I don’t think I get a very good miles-per-watt.

287 miles is lower than average but not abnormal if it stays there the next 10k miles.

 

[AAKEE]

287 miles is lower than average but not abnormal if it stays there the next 10k miles.

I also have 2018 M3 LR RWD, which was advertised as having 310 mile range. Just checked Tesla app and it’s showing 287 miles at 99%. (Or 230 miles at 79%). The car only has 8,700 miles and I’ve gone above 90% only a handful number of times. I plug it in every day and it’s set to charge to 80% (although I used to do 90%).

287 miles sounds low to me but I live on a hill so I don’t think I get a very good miles-per-watt.

When a car is used less then others the degradation from time will be the absolute dominant part.
The first two years will have a high part of degradation from time for other cars as well when driven average amount of miles per year:
You should/could compare with cars at the same age rather then using miles as the factor for degradation. It will look higher using *miles*.
One can think of not charging to a such high SOC if the car os briefly used.
I would only charge to 50-60% if I where you.
If your car is averaging >70% SOC you shold count with about 10% degradation från time during 3 years. Even if the car is not driven. Exact number is depending on SOC and temperature.

 

[Candleflame]

When a car is used less then others the degradation from time will be the absolute dominant part.
The first two years will have a high part of degradation from time for other cars as well when driven average amount of miles per year:
You should/could compare with cars at the same age rather then using miles as the factor for degradation. It will look higher using *miles*.
One can think of not charging to a such high SOC if the car os briefly used.
I would only charge to 50-60% if I where you.
If your car is averaging >70% SOC you shold count with about 10% degradation från time during 3 years. Even if the car is not driven. Exact number is depending on SOC and temperature.

it also gives further support to my theory that odometer reading has hardly any effect on degradation and most of it is time based.

If he sees 463kms he already has more than 10% degradation.

 

[AAKEE]

it also gives further support to my theory that odometer reading has hardly any effect on degradation and most of it is time based.

If he sees 463kms he already has more than 10% degradation.

Yes 10% was only a general statement.

We dont know the average SOC, and what ambient temps the car has been in other than ”earlier charge to 90%” and now 80%.

But 80-90% during three years(as I take it) with very low ODO-reading points at the higher degradation. First year should eat more than 5% even if at moderate temps.
At elevated temps first year can bite of 10%.

 

[AAKEE]

it also gives further support to my theory that odometer reading has hardly any effect on degradation and most of it is time based.

If he sees 463kms he already has more than 10% degradation.

I dug deep in my saved research reports to find one that is easy to read. Some are >100 pages and not that easy to read if not used to the technical terms around lithium battery chemistry. This is quite easy to read and not too long:
Lifetime analysis of EV Lithium batt

Some research reports do have wrong or partly wrong conclusions, for example can the setup of tests lead to conclusions that are not really valid. Reading a lot of Research and learning the things that is found In more than one report is good.

This report in mainly fine. They have most of the tests done with NCA-batteries In this test setup. The report is from 2015, but the results doesnt differ from mor recent tests of NCA.
The setup where they relate EFC/Equivalent Full Cycles refer to a car with quite small battery. They compare 500 EFC to 50000km. Thats 100km/62 miles range on a full charge so the example are set for a fairly small battery. For the example with 500EFC we should use the range from 100% down to the car stops times 500. For me that would be about 200.000 to 250.000km.
This also means that the power demand( ”C-rate”) is less in a Tesla than this theoretical short range car test so the degradation from the driving part should be slightly less(there are other research proving this, but to stick with one easy read report I give no reference for this statement).


I have an average SOC of about 35 to 40% when the car is not in use during a normal week. Average temp in my garage for a year is about 15C.
So I expect the calendar aging to be about 3% during the first 18 monts if I continue to use my charging schedule(Between 10 and 15C for between 30 and 40% SOC).

For the cyclic aging, 500 cycles is at least 200.000km. Im at 25000km right now and probably reach about 40.000-45.000km when the car is 18 months old. Thats roughly 100EFC or actually about 80, the degradation per cycle is small and its not that important to find the exact mileage.
Anyway, I would se about 1.5 to 2% degradation from the cyclic degradation As my charging scheduel put me close to the low SOC cycles.
Theres also a degradation add on for SuC, but I’m currently at about less then 20 sessions so that part is not big, and as this report refers to a small battery/short range, there is some headroom in the cyclic aging calc.
The total expected degradation is probably about 4.5%(to 5%) for the first 18 months for me.

If you use a higher SOC, for example 90% daily and have elevated temps, lets say 25 degrees average for the winter season and 40 for the summer season, the calendar aging would be about 8% for the first 18 months. This is also the case even if the car is not driven at all.

If you drive 80 to 100 cycles you would loose about 3% as you are in the high SOC according to the picture above.
This car would loose about 11% during the first 18 months.

We see that cyclic aging is the main degradation driver even if the car is driven more (twice) than the average car In Sweden(at least).
And we see that using a high SOC and letting the car be sleeping at that level eats a quite high portion of the capacity even if the car is not used, or driven only by a small amount. If the car is driven much more than average, still the calendar aging is at least twice the cyclic aging.

Calendar aging lessens with time so after a couple of years it seems to stabilize on a much smaller level.

You can calculate the aprox. degradation on your own Tesla(with NCA-batteries, which is more or less all except some 2021 SR+ at this date) with this. Remember that the degradation from temperature is not linear so its better to split the year in parts if there is a part of the year with 30-35 degrees C or more.

I calculated earlier that I would be around 2 to 2.5% degradation(another post in august or so, and maybe thread) after the holidays at 9 months and about 20000km, that should put my NFP at about 80kWh, or slightly below(79.9 today) and this is what I see since the latest F/W update So at least for me this calculation seems spot on.