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

[conv90]

If you leave it overnight sleeping with sentry off with single digit, does not need to be sub sero, and then charge to 90% and leave it sleeping for at least 2-3hrs?
And following days tjexsame but different SOC’s?

Yes, always sentry OFF during night. Yes sleeping sub zero and sleeping over 90%.
Following days , if the trend was Donward, it continued to be downward, If the trend was Upward, it continued to be Upward regardless of actions I made letting it sleep at low and high SOC.

You have been at quite low SOC all the time?
Only Supercharging, do you get a full preheat each time?
The car was a 2021 M3P from what date?

Basically I'm usually low SOC. I charge every 2 or 3 days from 10-15% to 55-60% (sometimes less thatn 10% sometime in the 25%).
When I decide to charge it (supercharge it because I still have 80.000 free superchargers km s from referral program) I'm at 25% but going to Supercharger I allow it to pre-heat loosing 5 or 6 or 7% in 12 km (the distance between my home and the local SuC V3).
It's a MARCH 2021 Performance model.

If your charging schedule produce a rolercoaster I suspect you could get a continued rolercoaster after a BMS calib.

I havent really bothered with BMS calibration, except for the two sleeps at -1.8/-2% to try to lower the NFP.
I guess other ppl is better of tipping about this, or follow that thread with ”how I got half my lost range back”.

No, just used one drive as an example, arrived at work after a 240km drive and did read 32%. After a days sleep it had 34%. A sign that the BMS was off on the pessimistic side.
I had a similar arriving at 52%, leaving 9 hours later I had 54%.


If the SOC adjusts down after longer drives following a sleep, it looks to me like the BMS is overestimating the capacity (if not too cold outside so the battery wont cool off very much).
I think it is possible to calculate the whereabouts of the true SOC if we know initial SOC, the kWh used, the arrival SOC and the after sleep SOC.

I disagree on this. I have always better NFP variations WHEN I see a lower Soc after a rest.
This is normal .
An exaggerated example:
Say 50% Soc and 240 km left. The car rests and you find it at 80% with the same 240 km range.
It means that the car losts NFP.
Instead if you find it at 20% and the km left are the same 240 , the NFP will go high.
Today I left it at 58% (after charging it) , I took it 3,5 hours later at 56,5% , the NFP went from 77 to 77,5.

 

[tony26]

A few people I know talked to me about an article that they found online about fast charging EV's. Here is the article from UC Riverside, Fast-charging damages electric car batteries.
Basically, what I was told and what the article says is fast charging an EV damages the batteries.

Is this really true? I'm having a hard time thinking it is with so many Tesla models on the road.

I will say that the article does not talk about Tesla Superchargers.

 

[KenC]

A few people I know talked to me about an article that they found online about fast charging EV's. Here is the article from UC Riverside, Fast-charging damages electric car batteries.
Basically, what I was told and what the article says is fast charging an EV damages the batteries.

Is this really true? I'm having a hard time thinking it is with so many Tesla models on the road.

I will say that the article does not talk about Tesla Superchargers.

Something weird about that research. The rate of deg has not been seen in practice. What were they doing?

"the industry fast-charging technique caused capacity to fade much faster— after 40 charging cycles the batteries kept only 60% of their storage capacity. Batteries charged using the internal resistance charging method retained more than 80% capacity after the 40th cycle.​

​

At 80% capacity, rechargeable lithium-ion batteries have reached the end of their use life for most purposes. Batteries charged using the industry fast-charging method reached this point after 25 charging cycles, while internal resistance method batteries were good for 36 cycles."​

 

[tony26]

Something weird about that research. The rate of deg has not been seen in practice. What were they doing?​

​

"the industry fast-charging technique caused capacity to fade much faster— after 40 charging cycles the batteries kept only 60% of their storage capacity. Batteries charged using the internal resistance charging method retained more than 80% capacity after the 40th cycle.​

​

At 80% capacity, rechargeable lithium-ion batteries have reached the end of their use life for most purposes. Batteries charged using the industry fast-charging method reached this point after 25 charging cycles, while internal resistance method batteries were good for 36 cycles."​

Yes, I find it very odd. My brother has had a model 3 for years and has not seen this at all. That's why I was wondering. It seems like the way they tested was not correct.

 

[PrometheusFire]

I have a question on this. I have posted on here and read most of the threads. I do a lot of miles in my model 3 long range, and understand there will be battery degradation over time. In a nutshell in the winter which of these is the less degrading:
Every day charging to 95% on AC with infrequent supercharging or charging on AC every day to 80-90% with supercharging nearly every day, meaning 2 charges most days in this second case. Your thoughts on this would be appreciated.

 

[KenC]

I have a question on this. I have posted on here and read most of the threads. I do a lot of miles in my model 3 long range, and understand there will be battery degradation over time. In a nutshell in the winter which of these is the less degrading:
Every day charging to 95% on AC with infrequent supercharging or charging on AC every day to 80-90% with supercharging nearly every day, meaning 2 charges most days in this second case. Your thoughts on this would be appreciated.

Sounds like you have a long drive. Personally, if you are trying to minimize degradation, keep your static charge level as low as possible, and just assume you need to charge on the road. Supercharging is relatively fine as long as you drive immediately after.

Since it sounds like 95% can get you to work and back, while anything lower, means having to top up a little. If that's the case, then I would charge to 60%-80% at home on AC, and just assume you need to top off for 5 mins at a Supercharger, at lowish SOC levels. That to me seems the best way to minimize degradation.

 

[dimovi]

So I did the battery test after 1 year and 18k miles and the battery health came at 96%, however at 100% SOC the reported range was 291, which does not make sense. The original EPA range is 315, so 291/315=92.4% which is quite a bit off from the reported 96% battery health. Any idea why it is different?

 

[3sr+buyer]

In a nutshell in the winter which of these is the less degrading:
Every day charging to 95% on AC with infrequent supercharging or charging on AC every day to 80-90% with supercharging nearly every day, meaning 2 charges most days in this second case. Your thoughts on this would be appreciated.

May not make too much of a difference. The second scenario may reduce the time spent at high (>55% for NCA, >70% for LFP) state of charge, but needing SuperCharging may increase degradation.

Of course, if you time your home charging to finish just before driving off, and you drive a lot early in the day so that it spends most of the day below 55% / 70%, then starting at 95% versus 80-90% may not add too much time at high state of charge. In that case, if starting at 95% avoids SuperCharging stops, that can be significantly lower cost in both time and money compared to having all of your charging at home (if your home charging is significantly less expensive than SuperCharging like it is for most people).

 

[Apprunner]

May not make too much of a difference. The second scenario may reduce the time spent at high (>55% for NCA, >70% for LFP) state of charge, but needing SuperCharging may increase degradation.

Of course, if you time your home charging to finish just before driving off, and you drive a lot early in the day so that it spends most of the day below 55% / 70%, then starting at 95% versus 80-90% may not add too much time at high state of charge. In that case, if starting at 95% avoids SuperCharging stops, that can be significantly lower cost in both time and money compared to having all of your charging at home (if your home charging is significantly less expensive than SuperCharging like it is for most people).

I believe it has been said in prior posts that charging to 95% vs. 80% is about the same level of stress to the battery. The time spent at 95% is probably much worse but if the car is driven immediately and spends most of the time below 60%, then it really doesn't matter if its 95% or 80% charge at home.

 

[EVDeepDive]

This thread is fascinating. Is there a TL;DR version? I only need about 10% charge every day. Should I just charge my 2023 MYLR upto 55% for my daily needs? It almost never drops below 40% at that charge limit before plugging it back in at home for then night.

 

[DrGriz]

This thread is fascinating. Is there a TL;DR version? I only need about 10% charge every day. Should I just charge my 2023 MYLR upto 55% for my daily needs? It almost never drops below 40% at that charge limit before plugging it back in at home for then night.

Yes.

 

[PrometheusFire]

I believe it has been said in prior posts that charging to 95% vs. 80% is about the same level of stress to the battery. The time spent at 95% is probably much worse but if the car is driven immediately and spends most of the time below 60%, then it really doesn't matter if its 95% or 80% charge at home.

Yes I always make sure that I work out that the car finishes charging no more than half an hour before I’m due to leave. I’ll give it half an hour in case there is a problem during the night but it’s always 33 miles/ an hour or thereabouts, so it’s easy to work out Because if you use the other message and let the car decide when to start charging to leave at a certain time it always seems to finish about an hour beforehand that’s why I do it myself, so it leaves little time from end of charge to starting off and it’s always over 100 miles, usually to my first call wherever that may be

 

[3sr+buyer]

Yes I always make sure that I work out that the car finishes charging no more than half an hour before I’m due to leave. I’ll give it half an hour in case there is a problem during the night but it’s always 33 miles/ an hour or thereabouts, so it’s easy to work out Because if you use the other message and let the car decide when to start charging to leave at a certain time it always seems to finish about an hour beforehand that’s why I do it myself, so it leaves little time from end of charge to starting off and it’s always over 100 miles, usually to my first call wherever that may be

In your day's driving, about how many hours after charging does the car get down to 55% state of charge or lower, for each starting charge level scenario (80%, 85%, 90%, 95%)?

 

[brainhouston]

So I did the battery test after 1 year and 18k miles and the battery health came at 96%, however at 100% SOC the reported range was 291, which does not make sense. The original EPA range is 315, so 291/315=92.4% which is quite a bit off from the reported 96% battery health. Any idea why it is different?

maybe they count the buffer in there?
i know on older legacy cars it was something like 4kW so could be those 4%, not sure how kW compares to % for your car...

 

[AAKEE]

So I did the battery test after 1 year and 18k miles and the battery health came at 96%, however at 100% SOC the reported range was 291, which does not make sense. The original EPA range is 315, so 291/315=92.4% which is quite a bit off from the reported 96% battery health. Any idea why it is different?

We need to learn what they mean with ”Battery health”.
Its clearly not the same as the expected when we relate to capacity.

[State of health] by industry standard is current capacity / original capacity.

If you have an M3P, the battery can loose some capacity (from the marked 82.1 kWh) before the range starts dropping.
291 mi = about 74.5 kwh capacity.
Thats 90.7%, so long from 96%.


How do you charge your car? What percent etc?
My ’21 M3P is two years, 55K km (34k mi) and I had 495km range(307 mi), 78.5 kWh capacity.

 

[AlanSubie4Life]

If you have an M3P, the battery can loose some capacity (from the marked 82.1 kWh) before the range starts dropping.
291 mi = about 74.5 kwh capacity.
Thats 90.7%, so long from 96%.

They’re probably just using 77.8kWh as the “reference” value for the test, even though that is completely wrong (for this vehicle).

It’s correct through 2020 though and that is good enough. The exact % result and output are probably not that important to Tesla as long as the measured value is good (which of course it is).

 

[AAKEE]

They’re probably just using 77.8kWh as the “reference” value for the test, even though that is completely wrong (for this vehicle).

It’s correct through 2020 though and that is good enough. The exact % result and output are probably not that important to Tesla as long as the measured value is good (which of course it is).

I would not be impressed if they missed to use the origin capacity…

It would set a LG 74.5 kWh battery back from start an my car would be above 100% (= report 100% then).

Off topic:
Well, Tesla still, after 1 1/2 year include the bug that reduce my SOC with ~ 5% by just changing to 18 or 19” tyres. Present range and full rated (SMT reported value reduce quite much also).

Perhaps the 18-19” Teslse refers to is not round but square

I have seen some other bugs with the latest software so in short I can not use these:
-AP
- Cruise control
- Auto high beam.

Starting to get really pissed about flawed software that force things to happen. Its a joke to have a car that you can not really rely on.

Shame on Tesla for this.
End off topic.

 

[alyuan]

I have access to a non Tesla 50kW fast charger in my neighbourhood, 5kms from my house. Car is LFP. How does it affect degradation, charging with a cold battery? Will I be better charging off from a 22kW? Thanks.

 

[AAKEE]

I have a question on this. I have posted on here and read most of the threads. I do a lot of miles in my model 3 long range, and understand there will be battery degradation over time. In a nutshell in the winter which of these is the less degrading:
Every day charging to 95% on AC with infrequent supercharging or charging on AC every day to 80-90% with supercharging nearly every day, meaning 2 charges most days in this second case. Your thoughts on this would be appreciated.

I do not get this.

It seems like you do not drive the car down very low, if 95% would do it on one charge, why charge two times to 80-90% on Supercharging?

How long is the drives between the charges?

If you charge to 95% AC, how much SOC do you arrive with?

The lowest degradation comes from small cycles that is ”placed” at low average SOC.
This means, using the lowest charging level you can do with a safe margin for range anxiety or to not be able to reach the destination.

For calendar aging, low SOC is also best so charge late befir the drive is best (low SOC during the night).

We have a Swedish M3P that do big cycles like 90% charging and ending up after the day with some close to 0%.
Earlierbit was 90-10% but a new situation called for this.
The car has done > 100k km (60k mi) and show about 71kWh just now but the BMS seems a bit of downwards.
It seems to do quite fine. A bit more wear from cyclic aging than others but lot less calendar, as it is charged late/just before the drive.

 

[PrometheusFire]

I do not get this.

It seems like you do not drive the car down very low, if 95% would do it on one charge, why charge two times to 80-90% on Supercharging?

How long is the drives between the charges?

If you charge to 95% AC, how much SOC do you arrive with?

The lowest degradation comes from small cycles that is ”placed” at low average SOC.
This means, using the lowest charging level you can do with a safe margin for range anxiety or to not be able to reach the destination.

For calendar aging, low SOC is also best so charge late befir the drive is best (low SOC during the night).

We have a Swedish M3P that do big cycles like 90% charging and ending up after the day with some close to 0%.
Earlierbit was 90-10% but a new situation called for this.
The car has done > 100k km (60k mi) and show about 71kWh just now but the BMS seems a bit of downwards.
It seems to do quite fine. A bit more wear from cyclic aging than others but lot less calendar, as it is charged late/just before the drive.

I do 2 or 3 surveys most days and average 1000 miles per week, sometimes i bit more. I picked my model 3 LR up on the 28th September this year and have done just over 12000 miles. I get up early to get back early as once back i have to create my surveys on a laptop at home. I do from 150-300 a day depending on where surveys are and like to get back with 70-120 miles so i can do most of charge for next day on off peak rate, between 00:30-7:30. As i have to up early i cant take advantage of all the off peak, as i usually depart between 4:45-5:15. My off peak is 8p and peak is 50.75p. As i have already said on here i make sure i time the charge to finish about half an hour before departure. Running the battery low on a regular basis is also not good