How I Recovered Half of my Battery's Lost Capacity

[KenC]

It has been hanging out at the recovered level with some variance.

So it appears that I have recovered some from the low point at around 30,500 miles, and it doesn't appear to be wanting to go down any further. Not a bad result.



Not really sure what you're getting at here. It sounds like "Well, if you disregard the evidence then this is meaningless".

Well. Ummm. Yes. I guess?

Doctor comes in and says "well the MRI shows you have a large cancerous tumor". Hmmm. Well I guess if I disregard the MRI results then everything should be OK.

My only thought is that your low point, at around 30,000 miles, you said was Jan 20, which is mid-Winter, and your recovery at around 36,000 miles was in April, early-Spring. Teslafi and the app I run, Stats, use the SOC api that is temperature-affected.

Here's my data from Stats, overlaid with temperature, that shows how much the 3rd-party apps, like TeslaFi and Stats, using the temp-affected SOC api, show BMS range estimates that correlate with temp change:

Now, strangely, since Jan 24th, the temp and BMS range estimate no longer seem to be correlated. I did get a bunch of software updates in this time period, so I do wonder if something changed, whether Stats decided to use the other SOC api that isn't temp-affected, or whether Tesla changed something. Dunno, but mid-Winter I expect the BMS estimate to show 304-306miles, and I'm currently getting 309-313miles, what I would normally show mid-Summer. Strange.

Anyway, just wondering if you ran your BMS data vs ambient temps to see if there's any correlation. Yes, I know, Houston, but as you can see, even small temp changes affect the BMS range estimate that 3rd-party apps seem to use.

 

[wildguess]

It has been hanging out at the recovered level with some variance.

So it appears that I have recovered some from the low point at around 30,500 miles, and it doesn't appear to be wanting to go down any further. Not a bad result.



Not really sure what you're getting at here. It sounds like "Well, if you disregard the evidence then this is meaningless".

Well. Ummm. Yes. I guess?

Doctor comes in and says "well the MRI shows you have a large cancerous tumor". Hmmm. Well I guess if I disregard the MRI results then everything should be OK.

Thank you for your response.
I am a little bit skeptical because your method did not work for me at all.
It must have made things even worse for me.
So, I am not sure if it works in general, or it was a coincidence that it worked for you.
I began using the same technique as you at around 24.5K.
At first the rated range growth exceeded my expectations, but a bit later it dropped to a quite low level and is not recovering no matter what I am doing (2019 SR+ , 240 miles EPA rating)

 

[KenC]

Thank you for your response.
I am a little bit skeptical because your method did not work for me at all.
It must have made things even worse for me.
So, I am not sure if it works in general, or it was a coincidence that it worked for you.
I began using the same technique as you at around 24.5K.
At first the rated range growth exceeded my expectations, but a bit later it dropped to a quite low level and is not recovering no matter what I am doing (2019 SR+ , 240 miles EPA rating)
View attachment 643467

What's the green line? Interesting that your variance increased substantially after around 32k.

 

[wildguess]

What's the green line? Interesting that your variance increased substantially after around 32k.

It is average range for same cars with similar mileage.
At 32,200 miles my car updated from 2020.40.8 to 2020.44.10.1.

When the car is parked or is sleeping the BMS recalculates the range and I often see the results such as below.
The percentage dropped while the range increased.

 

[AlanSubie4Life]

When the car is parked or is sleeping the BMS recalculates the range and I often see the results such as below.
The percentage dropped while the range increased.

Are you sure that's what TeslaFi is saying? To me it looks like it is just providing the math for you - that it went from 56% to 57% while sitting, for a -1% change in energy. Of course, it is possible for % to decrease while energy increases...but requires a fairly large change in nominal full pack - 8 rated miles in this case (and I don't see that in your plots).

But honestly, I have no idea (I don't use TeslaFi so not familiar with the reporting details and formats - seeing more datapoints and correlating with what the car says would explain what is happening though). And it's not uncommon for the BMS estimate to increase when the car sits. I don't know exactly what the mechanism is (rebalancing or just re-estimating?), but it happens. Decay can also happen, repeatedly (even without any actual vampire drain of significance). And the direction can depend on the specific SoC.

 

[RS69]

Hello All

i booked a service appointment as my m3 2020 sr+ is only showing 219 at 100% charging, my WH/m is 256 lifetime with 13652 miles on the clock. I received the following from tesla

Hi there Mr. Your range concern has been looked into and an appointment is not needed. We have carried out various checks and have a document to send you if you could provide us with an email ? Thanks Tesla Service

any ideas

 

[AlanSubie4Life]

Hello All

i booked a service appointment as my m3 2020 sr+ is only showing 219 at 100% charging, my WH/m is 256 lifetime with 13652 miles on the clock. I received the following from tesla

Hi there Mr. Your range concern has been looked into and an appointment is not needed. We have carried out various checks and have a document to send you if you could provide us with an email ? Thanks Tesla Service

any ideas

You have only lost 12% of your capacity. This is fairly normal. A bit on the high side, but quite normal. Hopefully it will slow down for you. Nothing you need to do.

 

[wildguess]

Hello All

i booked a service appointment as my m3 2020 sr+ is only showing 219 at 100% charging, my WH/m is 256 lifetime with 13652 miles on the clock. I received the following from tesla

Hi there Mr. Your range concern has been looked into and an appointment is not needed. We have carried out various checks and have a document to send you if you could provide us with an email ? Thanks Tesla Service

any ideas

I got the message "It is normal" from Tesla when I booked a service appointment with 204 miles at 100%.

 

[KenC]

My only thought is that your low point, at around 30,000 miles, you said was Jan 20, which is mid-Winter, and your recovery at around 36,000 miles was in April, early-Spring. Teslafi and the app I run, Stats, use the SOC api that is temperature-affected.

Here's my data from Stats, overlaid with temperature, that shows how much the 3rd-party apps, like TeslaFi and Stats, using the temp-affected SOC api, show BMS range estimates that correlate with temp change:
View attachment 643246
Now, strangely, since Jan 24th, the temp and BMS range estimate no longer seem to be correlated. I did get a bunch of software updates in this time period, so I do wonder if something changed, whether Stats decided to use the other SOC api that isn't temp-affected, or whether Tesla changed something. Dunno, but mid-Winter I expect the BMS estimate to show 304-306miles, and I'm currently getting 309-313miles, what I would normally show mid-Summer. Strange.

Anyway, just wondering if you ran your BMS data vs ambient temps to see if there's any correlation. Yes, I know, Houston, but as you can see, even small temp changes affect the BMS range estimate that 3rd-party apps seem to use.

DM'd with the Stats developer today, and the odd datapoints from end of January where the estimated Range went up, ~310miles, in the middle of Winter, when in the past it had stayed low, 304 miles, is because he switched SOC apis.

Of course, the old data is the old data, and it fluctuates based upon ambient temps; but the new data from end of January is now temp-independent. That, explains the odd gap between temp and estimated range that one can see at the very rightmost part of my chart. Here's the Stats chart. Red arrow points at where the SOC api changed, and my estimated range went from low 300s to 310+. I thought it was odd, now I know why.

 

[AlanSubie4Life]

DM'd with the Stats developer today, and the odd datapoints from end of January where the estimated Range went up, ~310miles, in the middle of Winter, when in the past it had stayed low, 304 miles, is because he switched SOC apis.

Of course, the old data is the old data, and it fluctuates based upon ambient temps; but the new data from end of January is now temp-independent. That, explains the odd gap between temp and estimated range that one can see at the very rightmost part of my chart. Here's the Stats chart. Red arrow points at where the SOC api changed, and my estimated range went from low 300s to 310+. I thought it was odd, now I know why.
View attachment 644694

Still 310 miles, lol. Crazy.

 

[Sklith]

My estimated range has been all over the place. I'm pretty disappointed how low it's gotten, though.

 

[Yankees]

First time posting here. I thought I had it all figured out and was basically doing the bat science-backed method of trying to have the battery stay around 50% for most of the time (by optimizing charging limits based on driving needs). My 310RM '18 LR AWD was doing great, sitting around 308-310 most of the time. Then, out of the blue, around 1/22/2021, things went south fast, and am having a hard time recovering:

https://imgur.com/DsbW00q

Off the low but still down low. Just took a recent 3000+ mile road trip (round trip) with nothing but supercharging (about 1.1MWh worth of energy) and it didn't really seem to have much of an effect -- if anything, it seemed to have helped a bit, and some of the SCing was to >90% because of headwinds and generally poor efficiency at 80+ MPH speeds (speed limit in West TX is 80 MPH). Now, this is not terrible as even the low point was less than 5%, but it's rather unexpected for me.

Based on my experience and what I've read, including this entire thread, I still believe that shallow cycling centered around 50% SoC is the best thing to do for the actual batteries. I'm curious to see if/how the warmer temps will affect things with the current APIs being temperature-independent (which could potentially mean they're now providing a more raw reading, which will fluctuate in warmer temps as the batteries most certainly are temperature dependent).

 

[KenC]

First time posting here. I thought I had it all figured out and was basically doing the bat science-backed method of trying to have the battery stay around 50% for most of the time (by optimizing charging limits based on driving needs). My 310RM '18 LR AWD was doing great, sitting around 308-310 most of the time. Then, out of the blue, around 1/22/2021, things went south fast, and am having a hard time recovering:

https://imgur.com/DsbW00q

Off the low but still down low. Just took a recent 3000+ mile road trip (round trip) with nothing but supercharging (about 1.1MWh worth of energy) and it didn't really seem to have much of an effect -- if anything, it seemed to have helped a bit, and some of the SCing was to >90% because of headwinds and generally poor efficiency at 80+ MPH speeds (speed limit in West TX is 80 MPH). Now, this is not terrible as even the low point was less than 5%, but it's rather unexpected for me.

Based on my experience and what I've read, including this entire thread, I still believe that shallow cycling centered around 50% SoC is the best thing to do for the actual batteries. I'm curious to see if/how the warmer temps will affect things with the current APIs being temperature-independent (which could potentially mean they're now providing a more raw reading, which will fluctuate in warmer temps as the batteries most certainly are temperature dependent).

Are you sure it didn't all go south on 1/20/2021, since on that day, clocks will spin backwards, and all sorts of palindromic mayhem takes place. You know, Palindrome Day.

All jokes aside, your battery did amazingly well for the longest time. Now, it's just doing above-average super well. I hope mine can do as well.

At least, your data is the 2nd we have that I can recall that shows shallow cycling below 60% leads to minimal degradation.

 

[Yankees]

Are you sure it didn't all go south on 1/20/2021, since on that day, clocks will spin backwards, and all sorts of palindromic mayhem takes place. You know, Palindrome Day.

All jokes aside, your battery did amazingly well for the longest time. Now, it's just doing above-average super well. I hope mine can do as well.

At least, your data is the 2nd we have that I can recall that shows shallow cycling below 60% leads to minimal degradation.

lol I’m sure it was palindrome day yad emordnilap saw ti erus m’I lol

To clarify, I'm not shallow cycling "below 60%," I'm optimizing my charging so that the battery sits closest to 50% for the longest amount of time. Example: some days I need to charge to 75%. On those days, I schedule charging to start in such a way that it'll charge the bat to 74% and not sit for more than ~1h before I drive out. My current covid driving is not go-to-work but more like drop off kids, pick them up later, then on some days drive them to extracurricular activities (groceries and the like are close enough that it's not worth taking into account). I've ended up preferring doing a larger yet-still-shallow charge vs multiple much-shallower charges, primarily because of convenience, but also to mix things up and not always have the bat cycle between very small SoC levels. So 74% on a day with 3 round trips would be:

• charge to 74% starting at like 4:30 AM
• drive out @ 7 AM, come right back home around 65-67% SoC; battery sits 15-17% away from 50% SoC for ~6 hours
• drive out @ 2 PM, come right back home around 57-59% SoC; battery sits 7-9% away from 50% SoC for ~1.5 hours
• drive out at 4:30 PM, come back a couple of hours later around 47-51% SoC; battery now sits 0-3% away from 50% SoC overnight
• sleep at arrival SoC till 4:30 AM, when it'll shallow charge again

On days with only two roundtrips (drop off/pickup w/o anything extra), I charge to ~67% in the absence of the 3rd roundtrip. Almost seems like software version did this, on 1/22/2021 I got 2020.48.35.5. The slide started on 12/11/2020, which is the day I got 2020.48.10.

 

[Rojer Lockless]

Fellow Houstonian here. I get random talk saying my battery is fine too. Kinda sucks when I've tried everything and a 90% charge sits at 259 or so on my LR RWD M3

 

[Candleflame]

You have only lost 12% of your capacity. This is fairly normal. A bit on the high side, but quite normal. Hopefully it will slow down for you. Nothing you need to do.

To call it normal is just you lieing to youself. 12% on essentially a fairly new car is rediculous. then Tesla needs to advertise their battery capacity and range taking that into account.

 

[Candleflame]

Adding to what Twiglett said, it's a difficult problem. The only real way to estimate battery capacity is a full charge and complete discharge on a special tool. The BMS does its best to indicate capacity with its readings. Itsynot a matter of Tesla being lazy

that is not really true. it has been shown multiple times that the BMS is extremely accurate.

 

[AlanSubie4Life]

To call it normal is just you lieing to youself. 12% on essentially a fairly new car is rediculous. then Tesla needs to advertise their battery capacity and range taking that into account.

It's literally normal; there is a normal distribution (though not exactly since it's truncated on one side so it's some other sort of distribution technically, maybe gamma). This is likely about 2.5-3 sigma out, on the bad side. I'm sure that people like TeslaFi and Stats keep stats on the actual distributions vs. age and mileage - unfortunately I haven't seen one of those plots in a long time. But my sense is that 12% is bad but not the worst, and certainly well within the normal range (I'd define outside the normal range as beyond 3 sigma, accounting for 99.7% of vehicles).

It's a lottery. My car shows 280-286 rated miles, about 10% capacity loss. It started out and stayed at 310 rated miles for quite a while (6 months or so). I personally know someone else who has slightly worse and they showed capacity loss much sooner.

The capacity advertised by Tesla is understood (to the knowledgeable buyer) to apply when the car is actually new. Not when it's a year old with 12000 miles on it. That's certainly "fairly new" by car standards, but not by battery standards. It's expected to degrade. I think owners should expect about 15% capacity loss over the first three years (just for budgeting reasons - many and probably most will do better, but this needs to be the expectation).

I think it's accurate to say that Tesla Model 3 batteries have degraded much more than people originally expected (many hoped they would be better than Model S since it was a new type of cell). But there's a spread. Some owners have relatively minimal loss at the same mileage and even older (though it can take a pretty big dump overnight if the CAC is determined to be low all of a sudden). It all depends on use, environmental conditions, and also a huge part appears to be luck or time of manufacture (good days and bad days at the battery factory). This isn't surprising at all for a manufacturing process that has to be tightly controlled. If the manufacturing control is slightly lost, but still within safe limits, you might see it down the road a bit.

But now we know: for the time being, until new cell types & chemistries show otherwise, or we have comprehensive data showing otherwise, expect more capacity loss from Model 3 & Y than from earlier vehicles.

 

[Candleflame]

It's literally normal; there is a normal distribution (though not exactly since it's truncated on one side so it's some other sort of distribution technically, maybe gamma). This is likely about 2.5-3 sigma out, on the bad side. I'm sure that people like TeslaFi and Stats keep stats on the actual distributions vs. age and mileage - unfortunately I haven't seen one of those plots in a long time. But my sense is that 12% is bad but not the worst, and certainly well within the normal range (I'd define outside the normal range as beyond 3 sigma, accounting for 99.7% of vehicles).

It's a lottery. My car shows 280-286 rated miles, about 10% capacity loss. It started out and stayed at 310 rated miles for quite a while (6 months or so). I personally know someone else who has slightly worse and they showed capacity loss much sooner.

The capacity advertised by Tesla is understood (to the knowledgeable buyer) to apply when the car is actually new. Not when it's a year old with 12000 miles on it. That's certainly "fairly new" by car standards, but not by battery standards. It's expected to degrade. I think owners should expect about 15% capacity loss over the first three years (just for budgeting reasons - many and probably most will do better, but this needs to be the expectation).

I think it's accurate to say that Tesla Model 3 batteries have degraded much more than people originally expected (many hoped they would be better than Model S since it was a new type of cell). But there's a spread. Some owners have relatively minimal loss at the same mileage and even older (though it can take a pretty big dump overnight if the CAC is determined to be low all of a sudden). It all depends on use, environmental conditions, and also a huge part appears to be luck or time of manufacture (good days and bad days at the battery factory). This isn't surprising at all for a manufacturing process that has to be tightly controlled. If the manufacturing control is slightly lost, but still within safe limits, you might see it down the road a bit.

But now we know: for the time being, until new cell types & chemistries show otherwise, or we have comprehensive data showing otherwise, expect more capacity loss from Model 3 & Y than from earlier vehicles.

ok, what if your car degrades to 29% now. are you happy with that, because"it is normal" on your 1 year old car?
i dont think so buddy. it is misleading advertising. nowhere on teslas websites does it state that after a year you get 70km less rated range after a year. it's very close to being fraud. nevermind that if you did your own research you mainly saw degradation data from the model s which looked very promising with 5% after many years and many kms. If you bought the vehicle assuming that you i.e. can do a 350km trip on one charge and now you are struggeling then tesla has not been truthful about how much range degradation their vehicles have.

Also even by Teslafi standards 12% is not normal. The average for 30k km is around 5-6% atm.

 

[AAKEE]

Hello All

i booked a service appointment as my m3 2020 sr+ is only showing 219 at 100% charging, my WH/m is 256 lifetime with 13652 miles on the clock. I received the following from tesla

Hi there Mr. Your range concern has been looked into and an appointment is not needed. We have carried out various checks and have a document to send you if you could provide us with an email ? Thanks Tesla Service

any ideas

I see that my range number on the app doesnt show the same as the car range. There was an change in the firmware which changed the screen range from 499-500km to 507km, probably an adjustment to set the screen range to the EPA value. This is not updated in the app ant it still show 500km, which is less then the actual epa range.

Whats the official EPA range of your car?
Whats the actuall range for your car on the screen at 100% charge ? (You maybe could provide us with the projected range on the screen(not app) and the SOC at the same time, preferably 70% or more, then we can calculate the 100% range from that)
Whats the actuall range for a new SR+ on the screen at 100% charge ?

I think theres a possibillity that we are comparring apples with pears ?