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

[AAKEE]

How am I doing on degradation? Well, after over a year...

One year might be a little short time to establish differences.

I still have full range(507km) after 40.000km/25.000mi and 16 months.
Teslafi is not very exact down to the mile because they have limited data(rounded SOC) to do the range calculation. Still full range on every full charge

Most people think that “the miles” that is the main factor for degradation. Its not.

Specially the first years(5 or so) the calendar aging is the bigger part of the cars loss of range (see the calendar aging graph in my last post above).

Depending on the climate, people mostly have 3-4 to 8% the first year and then gradually reducing rate after that.

The cyclic aging for most people is around the 1% mark. Most people probably is below, buth people driving much each year with bigger cycles might use up 1-2% or so.

Remember, NCA cells typically loose 20% capacity for 500-750 or so cycles with 100-0%, and perhaps hold up at least 2000-3000 full equivalent cycles with normal use. 2000 cycles is some 1.000.000km for a LR or P so driving 20.000km/ 12500mi each year will eat 20.000/1.000.000 = 2%
Smaller cycles will degrade the battery less, fir the same amount of miles.

 

[AAKEE]

Why does it matter if it's the Tesla manual or not? It's an academic publication on what causes Li-ion degradation, and applies to all Li-ion batteries.

Overdischarging != low SoC. They are related, but low SoC without overdischarging only causes cathode degradation as per that picture. Go into the overdischarge range and you start also getting anode and inactive material degradation. It's obvious that high SoC is even worse than low SoC because high SoC (without overcharging) shows up as a cause for all 3 methods of degradation: anode degradation, cathode degradation, and inactive material degradation. But that does not mean that low SoC, by itself, doesn't cause degradation.

If you want to minimize degradation, keep your battery close to the center of its SoC range, not at the extreme low end. Intuitively, we can sort of understand this as the extreme low SoC range is just outside the "overdischarged" range, and there aren't really any step functions in physics outside of quantum mechanics.

No, you are wrong.

You need to widen the focus and read research. There is nothing wrong with that document but you interpretate it wrong.

 

[AAKEE]

Tesla use Panasonic lithium batteries with NCA chemistry.
Here is an example of a research report about calendar aging of NCA cells:

Calendar aging NCA

There is a lot of research reports, they basically show the same thing. In some cases, the researchers did the wrong conclusions because the test setup was wrong(or masked a fact) but the numerical values of all research fit in with the others.
For example is there one report finding that cycling around about 50% or so is best.
But the problem is that the test setup had 50 and 65 and 80%. No low SOC test was made. The conclusion should be that 50% gives the lowest degradation of 50, 65 and 80% SOC and not that 50% offers the lowest degradation of all possible SOC’s.

This report covers cycling with NCA:
Cyclic aging not below 20%, but the low cycle is 20-45% and degrade least of the three.

SOC Window research report

Cyclic aging s.51 and on

Cyclic aging 5-25%(lowest) best of tested

Avoid eegradation by avoiding high SOC

 

[jyavenard]

So I charged to 100% and it will only go to 295 Miles. I

you don't say what car you have and its build date. So can't comment.

295 miles would be much better than my car (July 2019 build) which only gives me 464km (288 miles)

 

[jyavenard]

Charged to 100% yesterday before going on a 310km journey.
I averaged 145Wh/km which is pretty good all things considered (2019 Performance with 19" sports wheel). I had the heater off most of the time, only using the seat heater (it was 15C outside, winter is coming)

Before starting it showed 70kWh capacity (70.3kWh nominal remaining: no idea where it gets that from).

At the end of the journey, with 34% battery left it showed:

so a 9.7% degradation from new if considering the battery capacity.
Or:
7.6% drop from the original 499km showing at 100% (461km today)

 

[NQRDDS]

My apologies if this has been discussed before but I couldn't find a thread for the LR and my model year. I have a 2022 M3 LR and I noticed during charging with the slider pulled all the way to 100% that my estimated range is around 334 mi. At 90% it's at 301 mi. Is this normal? I'm assuming the car also takes into consideration my overall average driving style and calculates it to be that way? I do a lot of highway driving and try to keep an average of 75 mph but there are moments that I go a little over 80 mph depending on the speed of traffic. I understand that's not ideal for range but was curious if that has affected my car's estimated range at 100%. Appreciate the help and sorry again if this has already been discussed.

 

[ucmndd]

I have a 2022 M3 LR and I noticed during charging with the slider pulled all the way to 100% that my estimated range is around 334 mi. At 90% it's at 301 mi. Is this normal?

Do you have 19” wheels? If so, 334 miles is exactly the mileage your car is rated for from the factory.

I'm assuming the car also takes into consideration my overall average driving style and calculates it to be that way?

This is an incorrect assumption.

 

[NQRDDS]

Do you have 19” wheels? If so, 334 miles is exactly the mileage your car is rated for from the factory.


This is an incorrect assumption.

Thanks for clarifying. I forgot to mention that I actually have the 18” aero wheels. What estimation should I see?

 

[ucmndd]

The long and short of it is it’s “normal” either way. Charging habits can impact the displayed range… battery degradation will be the most pronounced in the first year or so, etc etc.

There’s nothing “wrong” with your car and if you take it to Tesla they’ll tell you everything is fine.

The “range loss over time” master thread pinned to the top of this forum has 5,000+ posts covering this topic. You might want to start reading in there (start with the last few pages).

 

[NQRDDS]

The long and short of it is it’s “normal” either way. Charging habits can impact the displayed range… battery degradation will be the most pronounced in the first year or so, etc etc.

There’s nothing “wrong” with your car and if you take it to Tesla they’ll tell you everything is fine.

The “range loss over time” master thread pinned to the top of this forum has 5,000+ posts covering this topic. You might want to start reading in there (start with the last few pages).

Got it, thank you! I appreciate you guiding me in the right direction. I normally charge with a level 2 ChargePoint station at my apartment complex and is capped at 90% for daily use. The car is also rarely supercharged. The last time was yesterday when I went on a short road trip but in total probably 2-3 times since November 2021.

 

[jjrandorin]

My apologies if this has been discussed before but I couldn't find a thread for the LR and my model year.

Thats because, in general, for LR AWD and Performance model 3s, its all the same discussion, which is why its all in this one (very large) thread, where your post was moved to.

The only one thats different in model 3s is the current "RWD" which has a LFP battery. There is a separate thread for that range discussion but other than that, this thread is the one, and anything on range posted outside of this thread in model 3 subforum will likely end up here if I see it.

 

[NQRDDS]

Thats because, in general, for LR AWD and Performance model 3s, its all the same discussion, which is why its all in this one (very large) thread, where your post was moved to.

The only one thats different in model 3s is the current "RWD" which has a LFP battery. There is a separate thread for that range discussion but other than that, this thread is the one, and anything on range posted outside of this thread in model 3 subforum will likely end up here if I see it.

Thank you, that makes sense. I appreciate you moving my question to the appropriate thread!

 

[jjrandorin]

Thank you, that makes sense. I appreciate you moving my question to the appropriate thread!

Sure, np.

As for your original question, @ucmndd already addressed that, but in general, "speed kills range" and its not a little bit, either. Going 75 is not a "little more electricity usage" than 70, its a lot, and same from 75-80. All that is normal, and teslas rated range at 100% is not impacted by a "guessometer" like some other cars.

There isnt anything wrong with your car, though, which is usually the concern.

 

[NQRDDS]

Sure, np.

As for your original question, @ucmndd already addressed that, but in general, "speed kills range" and its not a little bit, either. Going 75 is not a "little more electricity usage" than 70, its a lot, and same from 75-80. All that is normal, and teslas rated range at 100% is not impacted by a "guessometer" like some other cars.

There isnt anything wrong with your car, though, which is usually the concern.

Thanks for the clarification, that coincides with why I use much less electricity when I commute during rush hour and sit in traffic most of the way . That puts my worry to rest

 

[AAKEE]

Charged to 100% yesterday before going on a 310km journey.

(70.3kWh nominal remaining: no idea where it gets that from).

Nominal Full pack (NFP) is the BMS estimated capacity of the battery.
Nominal remaining is the actual stored energy, estimated by the BMS.
Its not uncommon that the nominal remaining exceeds the NFP by 0.5kWh or so.
Nominal remaining is the base for showing the SOC and also the on screen range.
Nominal remaining is sort of divided by the constant (152.X in your car) to get the range.

so a 9.7% degradation from new if considering the battery capacity.
Or:
7.6% drop from the original 499km showing at 100% (461km today)

Your car shows full range (500km) down to a nominal remaining of about 76kWh. Theres about 1.8kWh of degradation masked in the km-reading from this.

1-(70.3/77.8)= 9.6% should be the best way to calculate the degradation.

To see the real degradation driving from 100% until the car stops could give a better measure, but as there are a few other factors, like losses not shown (the word is 0.5-1 kWh?) one need to do it on the car when new to have a comparable number.

 

[jyavenard]

To see the real degradation driving from 100% until the car stops could give a better measure, but as there are a few other factors, like losses not shown (the word is 0.5-1 kWh?) one need to do it on the car when new to have a comparable number.

I would have needed to do that when I first got the car (and back then I would have been too much of a chicken to try); and then find the exact same route with exact same weather conditions: all of which is just impossible.

Battery is now showing at 70.4kWh today, so a tiny bit more than 9.5% degradation... Not too bad I guess in the 2.5 years I've got the car

 

[FlatSix911]

Here you go: https://css.umich.edu/sites/default/files/publication/CSS20-08.pdf
"Low state of charge/overdischarge" is one of the contributing factors to degradation. The mechanisms that cause degradation under these conditions are shown in the picture on page 4.
In general, for any longer trip, I'll try to center the battery around 50% SoC. For example, if I expect a trip to use 60% SoC, I'll charge to 80% so I can arrive back with 20%. If I expect it to use 50%, then the battery gets charged to 75% and I arrive back with 25%. And so on. However, since it seems like higher SoC is worse than lower SoC, I set Scheduled Departure for just before I leave, such that the battery sits at the lower arrival SoC longer than it sits at the higher departure SoC. For local driving, 60% is always used as the charge limit. How am I doing on degradation? Well, after over a year...

Your interpretation is correct... thanks for sharing.

"4.4. Electric vehicles BMW, Chevrolet, Ford, Fiat, Honda, Hyundai, Kia, Mercedes-Benz, Nissan, and Tesla all include information about batteries in their owner's manuals. The most commonly identified sources of degradation are (in order): high temperature [124–133], low temperature [124–127,129–133], overdischarge [124,125,127–132], and fast charging [125,127,129,130]."

 

[ShelJW]

Just have a quick question...

I've been plugging my Tesla (it's a Model Y, but it doesn't matter for this question) in at the end of the day, around 6 or 7pm, if I'm not planning to go out again. I leave it charging overnight, then unplug it at around 7am the following day when I take my daughter to school.

My son, who now has a Model 3 on order, tells me that I should plug my car in whenever I'm at home, that Tesla recommends the car be charged whenever possible ( I work from home, so I'm coming and going at different times of the day)

I use the Tesla home charger, if that matters.

Just wondering, do most of you who have a level 2 home charger simply plug your car in at the end of the day, and leave it plugged in overnight, or if you happen to get home in the middle of the day, do you plug it in for an hour, 90 minutes, if you're going to go out again?

Just wondering... I doubt it has major impact on the battery, but may as well do what's best. Fully charged (to 80%) gives me around 245 miles of range, more then enough for my average day.

Thanks in advance!

 

[AAKEE]

Your interpretation is correct... thanks for sharing.

"4.4. Electric vehicles BMW, Chevrolet, Ford, Fiat, Honda, Hyundai, Kia, Mercedes-Benz, Nissan, and Tesla all include information about batteries in their owner's manuals. The most commonly identified sources of degradation are (in order): high temperature [124–133], low temperature [124–127,129–133], overdischarge [124,125,127–132], and fast charging [125,127,129,130]."

Define ”overdischarge” for your self.

The battery manufacturers and researchers define it as discharging the battery cell beyond the designed limit.

We can not discharge the battery beyond the limit as the car will shut down the battery via the cobtactors before we reach that limit. Thats also, correct, stated in the document STS-134 refers to:

The same document refers to this test:

Its only one of very many showing the same thing.
How come the battery cycled down to 0% SOC has the absolutely, by a wide margin, the lowest degradation?
Cycled down to 0% caused 3% degradation. Cycled down to 20% has 9% degradation.
How would the battery thats cycled to 20% have 3X degradation if the one cycled in the dangerous ”overdischarge” region ?

If you start reading resesrch reports you will find that:
100% SOC = the state with the maximum cell voltage
0% SOC = the state with lowest cell voltage(actually stopped discharging at lowest voltage, and regains voltage at rest after the discharge cycle.
Capacity = the energy delivered between 100 and 0% SOC.

Overdischarge= discharging the battery beyond the specified limit.

There is also research reports about overdischarge. For batterys with 2.5V discharge limit there was hardly any damage detected if discharged down to 2.0 Volts. The damage occured if dischsrged to lower than 2.0V.

ALL data show that 0% is safe. 0% is not overdischarge.

 

[Apprunner]

Just have a quick question...

I've been plugging my Tesla (it's a Model Y, but it doesn't matter for this question) in at the end of the day, around 6 or 7pm, if I'm not planning to go out again. I leave it charging overnight, then unplug it at around 7am the following day when I take my daughter to school.

My son, who now has a Model 3 on order, tells me that I should plug my car in whenever I'm at home, that Tesla recommends the car be charged whenever possible ( I work from home, so I'm coming and going at different times of the day)

I use the Tesla home charger, if that matters.

Just wondering, do most of you who have a level 2 home charger simply plug your car in at the end of the day, and leave it plugged in overnight, or if you happen to get home in the middle of the day, do you plug it in for an hour, 90 minutes, if you're going to go out again?

Just wondering... I doubt it has major impact on the battery, but may as well do what's best. Fully charged (to 80%) gives me around 245 miles of range, more then enough for my average day.

Thanks in advance!

Don't overthink it. What you are doing is perfectly fine. Your way is probably better if the limit of the charge is at 80% meaning its probably better for the battery if you tend to use it throughout the day and the average SoC is 50% than it is to constantly go from 80% to 70% back to 80%. If you read through this large thread, you'll see calendar aging due to higher avg SoC is a bigger factor than cyclic use and calendar aging is primarily driven by what the average SoC is during the day.

If you don't need the full 80% for the day and you only tend to use 20-30%, you may want to consider taking the charge down to 60-70% if that works for you. If it doesn't don't worry about it.