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My 1 month old model 3 loses 4-5% battery parking overnight

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Thanks for that info about SOC Min. So, what are the other SOC values? SOC Max, SOC UI, SOC Avg?
I did not bother to try figuring it out. I know I did read some text from the people behind Scan My Tesla and they did not know either.

In any case, knowing true SOC and how it differs from displayed SOC should be enough for *any* thing we could think of so I suggest to disregard these numbers.
 
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@AAKEE Thanks for all the data you presented in this forum. It’s the most valuable information I’ve encountered. By any chance do you have any information on supercharging and it’s effect on battery degradation? Thanks.

Well, it will not be easy to show exact numbers, but principles is easier.

The main degradation that comes from charging is lithium plating. With a cold battery the lithium ions can not move very quick so a high charging current causes the lithium ions to stuck up to blobs like a traffic jam. The warmer the battery the more freely the lithium ions can flow, not causing any blobs.

Most research test degradation from fast charging cycles with non heated cells, so 25C or so. They also mostly do fixed current charges until the charging voltage reach 4.2V, and tesla reduce the charging power a bit more than this at it seems.

There is research reports that shows that preheating the cells to 40C or more reduce the lithium plating to a minimum.
At 1C charing rate (80kW for a 80kWh battery etc.) we need to have a battery temperature above 20C, and as we charge with about 3-3.5C at the fastest rate in a SuC V3 we need to have a higher battery temp.

I always preheat completely, when possible. I know Tesla reduces the charging speed if the battery was not preheated, but still I think the best thing should be to make a conmplete preheating.
Tesla did change the cell temp target recently, before I think all SuC had 48C target but now that is only SuC V3 (250kW).
For SuC V2(150kW) my car reaches 42C before the charging.

With a complete preheating I think a supercharging session doesnt hurt that much.
C8F617A5-6FC5-4E8A-9230-25E989985E2D.jpeg


We can se below from a research report that charging currents up to 1A at temperature 25C. (about 0.3C on these 2.8Ah 18650 NCA) will give about the same cycle life, so reducing below 0.3C or about 20-25kW will not reduce the wear noticable.

We can also see that a lower charging target clearly reduces the wear (less lithium plating). Tesla charge quite slow at high SOC anyway, probably to protect from lithium plating. It is anyway a good idea to not charge to a higher SOC than needed.

high charging currents lead to a rapid degradation due to lithium plating, which occurs particularly strongly at high SoC.

With Teslas Superchargers, the 3C is only present to about 20-25% SOC, over this the charging power reduces so we can probably assume a average between 2 and 3C. Remember that below is charging at high rates at 25C, and this we know is not warm enough to counter lithium plating. If we look at the wear as an average between 2 and 3C we will find that the wear is about double compared to slow charging For the 4.0V charging target (4.0V is about 80%). The battery will stand 500 cycles instead of 1000 cycles.

If we use a lower charging target than 4.0V / 80% the cyclic aging would probably reduce to less than double compared to the slow cxharging.
If we use a complete preconditioning the battery will be warm enough to reduce the most of the lithium plating, so the difference between slow charging and supercharging reduces further.
—> Stay low in SOC and precondition completely.

Remember that cyclic aging is not a very big part of the battery degradation for the first five years, so a small number doubled is till quite small.
44BFB09E-ACE4-4045-809D-28488194E29E.jpeg



I have some 30+ full charges and about 45 Supercharging sessions. Still my car shows a capacity that is very close to the calendar aging number. This means that the 45 Supercharging sessions that is about 17-18% of the total energy charged has not caused a noticable degradation to my cars battery. Of course, if I had not supercharged ever, and never charged full the battery capacity would be higher, but not with much as it is the calendar aging that takes the big bites even for my car that has quite low degradation.

One thing that might have helped my degradation from supercharging to stay low can be read below. I know this exists, there is some research reports that touch the subject but I havent dug into it.

As my car normally sleeps with 20-50% or so, and do use small cycles except when driving longer the battery probably get the regeneration we can read about below. There is numbers on this but I do not have the reports available here.

F602B689-0A5B-4BFF-971F-E73C03B7460A.jpeg



I would say that if supercharging when needed flor trips, and not every day we will not notice any extra degradation from this.
To reduce the wear:
-Preheat completely
-Arrive with low SOC.
-Better with two Supercharging sessions with 50% charging than one with 100%.

Remember that just having the car parked with 80-90% SOC most of the days for the first year will cause much more degradation than a lot of supercharging sessions.

Link to research report

I always preheat and I do not hesitate at all to supercharge. When needed I’m glad to.
 
Well, it will not be easy to show exact numbers, but principles is easier.

The main degradation that comes from charging is lithium plating. With a cold battery the lithium ions can not move very quick so a high charging current causes the lithium ions to stuck up to blobs like a traffic jam. The warmer the battery the more freely the lithium ions can flow, not causing any blobs.

Most research test degradation from fast charging cycles with non heated cells, so 25C or so. They also mostly do fixed current charges until the charging voltage reach 4.2V, and tesla reduce the charging power a bit more than this at it seems.

There is research reports that shows that preheating the cells to 40C or more reduce the lithium plating to a minimum.
At 1C charing rate (80kW for a 80kWh battery etc.) we need to have a battery temperature above 20C, and as we charge with about 3-3.5C at the fastest rate in a SuC V3 we need to have a higher battery temp.

I always preheat completely, when possible. I know Tesla reduces the charging speed if the battery was not preheated, but still I think the best thing should be to make a conmplete preheating.
Tesla did change the cell temp target recently, before I think all SuC had 48C target but now that is only SuC V3 (250kW).
For SuC V2(150kW) my car reaches 42C before the charging.

With a complete preheating I think a supercharging session doesnt hurt that much.
View attachment 898573

We can se below from a research report that charging currents up to 1A at temperature 25C. (about 0.3C on these 2.8Ah 18650 NCA) will give about the same cycle life, so reducing below 0.3C or about 20-25kW will not reduce the wear noticable.

We can also see that a lower charging target clearly reduces the wear (less lithium plating). Tesla charge quite slow at high SOC anyway, probably to protect from lithium plating. It is anyway a good idea to not charge to a higher SOC than needed.



With Teslas Superchargers, the 3C is only present to about 20-25% SOC, over this the charging power reduces so we can probably assume a average between 2 and 3C. Remember that below is charging at high rates at 25C, and this we know is not warm enough to counter lithium plating. If we look at the wear as an average between 2 and 3C we will find that the wear is about double compared to slow charging For the 4.0V charging target (4.0V is about 80%). The battery will stand 500 cycles instead of 1000 cycles.

If we use a lower charging target than 4.0V / 80% the cyclic aging would probably reduce to less than double compared to the slow cxharging.
If we use a complete preconditioning the battery will be warm enough to reduce the most of the lithium plating, so the difference between slow charging and supercharging reduces further.
—> Stay low in SOC and precondition completely.

Remember that cyclic aging is not a very big part of the battery degradation for the first five years, so a small number doubled is till quite small.
View attachment 898574


I have some 30+ full charges and about 45 Supercharging sessions. Still my car shows a capacity that is very close to the calendar aging number. This means that the 45 Supercharging sessions that is about 17-18% of the total energy charged has not caused a noticable degradation to my cars battery. Of course, if I had not supercharged ever, and never charged full the battery capacity would be higher, but not with much as it is the calendar aging that takes the big bites even for my car that has quite low degradation.

One thing that might have helped my degradation from supercharging to stay low can be read below. I know this exists, there is some research reports that touch the subject but I havent dug into it.

As my car normally sleeps with 20-50% or so, and do use small cycles except when driving longer the battery probably get the regeneration we can read about below. There is numbers on this but I do not have the reports available here.

View attachment 898596


I would say that if supercharging when needed flor trips, and not every day we will not notice any extra degradation from this.
To reduce the wear:
-Preheat completely
-Arrive with low SOC.
-Better with two Supercharging sessions with 50% charging than one with 100%.

Remember that just having the car parked with 80-90% SOC most of the days for the first year will cause much more degradation than a lot of supercharging sessions.

Link to research report

I always preheat and I do not hesitate at all to supercharge. When needed I’m glad to.
Thanks. Again, you did not disappoint with clear data presentation. I have a question if you don't mind. How do you check for the state of your battery's temperature? Tesla has no preheating on demand and the only way to do it is to route to a SC and usually end up preheating partially on arrival. So how to do you get it to arrive at SC station completely heated.
 
Thanks. Again, you did not disappoint with clear data presentation. I have a question if you don't mind. How do you check for the state of your battery's temperature? Tesla has no preheating on demand and the only way to do it is to route to a SC and usually end up preheating partially on arrival. So how to do you get it to arrive at SC station completely heated.
As AlanSubie says Scan my Tesla shows battery temperature.
I also use teslalogger to log all SMT data.

I have a extra screen that show SMT data.
A1283C75-179C-4E11-B675-88DA2BA78728.jpeg
 
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@AAKEE
Over the weekend , I tried to force preconditioning by picking the a Tesla Supercharger for my next stop. It however wouldn't do it instead I get this while charging:

View attachment 901889
It continues to heat the battery initially during supercharging, until the battery is 56-58C or so and start to need cooling.

You would not get 207kW at 20% if the battery was not quite warm. Seems like there was not enough time to reach the complete preheated batterypack of 48C or so.
But it sure was preconditioned if you did get 207kW.

Edit, just saw…it is an X.

What year snd battery? I would guess most of the S/X would not reach 250kW? At least if not the newest version
 
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It continues to heat the battery initially during supercharging, until the battery is 56-58C or so and start to need cooling.

You would not get 207kW at 20% if the battery was not quite warm. Seems like there was not enough time to reach the complete preheated batterypack of 48C or so.
But it sure was preconditioned if you did get 207kW.

Edit, just saw…it is an X.

What year snd battery? I would guess most of the S/X would not reach 250kW? At least if not the newest version
It's 2023 and it does 250kw. I've tried placing the supercharger as destination for >30mins prior to arrival and still will not precondition. FYI, I've been driving for >1 hour.
 
It's 2023 and it does 250kw. I've tried placing the supercharger as destination for >30mins prior to arrival and still will not precondition. FYI, I've been driving for >1 hour.
I have a lot of qualitative data on supercharging and preheating.

M3P 2021, not the same car, but a lot should be the same.
1) Its not possible to get 207 kW without preheating. Maybe in the summer in a hot day, driving fast, but not else.
2) The M3P will heat the battery with about 1 degree C / minute until the battery reach 40C. After that the heat ramps slower. 48C or so is the target and needed to get full charging power. This calls for closer to one hour to preheat completely.
3) Cars with heatpumps suck the heat from the battery generated generated by heat loss from driving. The battery will be colder during time when the cabin need to be heated (whenever possible the battery heat will be used). My car suck the heat down to 11-12C and then let the battery heat from driving, at 17C batt temp it suck the heat again.
If you did have a non heat pump tesla before, the heat pump car will most probably have a colder battery to begin with, increasing the time needed to oreheat completely.

Might not be the same issue for you but the most common question in a swedish facebook tesla forum is “slow charging speed” and the solution is so far each time to give the car the time needed to preheat the battery.
 
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It's 2023 and it does 250kw. I've tried placing the supercharger as destination for >30mins prior to arrival and still will not precondition. FYI, I've been driving for >1 hour.
Not really sure what you are saying. You said “still will not precondition,” which implies it does not say it is preconditioning, and you cannot hear the obvious accompaniment of noises. Is that true or not?

Of course you should not expect max charging speed after preconditioning!!! That would only happen if the battery is warm enough and all other conditions are met, which does not occur all the time in the general case even after high speed travel with extensive pre-conditioning.
 
Heres a drive in not that cold WX. It was around 0C all the drive. The batt temp started at about 10C, and ended at 19C ( the car increases the batt temp at low SOC to reduce the powwer loss. Two hours after the start of the drive the batt temp was 15C.

We do not get any heat for free when we drive in colder than 15C or so, as the heat pump steals the heat.
batttemp2.png
 
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Here a supercharging session, car parked some days and a one hour drive to the SuC V3, I started the navigation to the supercharger before rolling.
It took a few minutes before it started to preheat the battery with high power, but when it did the increse was 1C per minute (29C change from 13:15 to 13:45.

If we use these two charts together (this and the one from the earlier post) we can see that even a long drive will not give a warm battery unless it is hot enought that the cabin doesnt need preheating. After 1-2hours driving we can have a batt temp of 11-12C if it is at the lowest point that the heat pump suck it down to.

We also can see that 30 minutes will not be good enough to reach the temperature target for the battery durring winter time.
During this charge the top charging power was 250.07kW but the car did show 258kW as there still was battery heating on during the early part of the charging session.
SuC_V3.png
 
Not really sure what you are saying. You said “still will not precondition,” which implies it does not say it is preconditioning, and you cannot hear the obvious accompaniment of noises. Is that true or not?

Of course you should not expect max charging speed after preconditioning!!! That would only happen if the battery is warm enough and all other conditions are met, which does not occur all the time in the general case even after high speed travel with extensive pre-conditioning.
1. Yes and I wonder why Tesla wouldn't automatically precondition prior to arrival at SC location. I was travelling for >1 hour prior to arrival on NOA. The car decided to heat the battery while charging instead
2. I was more concerned about why Tesla is not preconditioning the battery before arriving at the supercharger location.
 
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Well, the reason why Tesla shouldn't pre-condition the battery before arriving at a SC, is because it uses a LOT of energy. And, some people driving to a SC are at low SOC, and pre-conditioning might make the situation worse. Of course, then the next question is, can't the car tell if you're super low on charge, not to pre-condition automagically? You're right, the car should figure it out.
 
1. Yes and I wonder why Tesla wouldn't automatically precondition prior to arrival at SC location. I was travelling for >1 hour prior to arrival on NOA. The car decided to heat the battery while charging instead
2. I was more concerned about why Tesla is not preconditioning the battery before arriving at the supercharger location.

You’re not actually answering the question. If you navigate to a Supercharger it should precondition. As I said, it may not be sufficient for max rate, which is fine - completely normal for more heating to occur at the Supercharger - heating at SC does not imply the car was not preconditioned, just that it was not fully so.

It should clearly state (and be extremely obvious from the tremendous amount of noise) that it is preconditioning on the nav screen.
 
You’re not actually answering the question. If you navigate to a Supercharger it should precondition. As I said, it may not be sufficient for max rate, which is fine - completely normal for more heating to occur at the Supercharger - heating at SC does not imply the car was not preconditioned, just that it was not fully so.

It should clearly state (and be extremely obvious from the tremendous amount of noise) that it is preconditioning on the nav screen.
It was not preconditioning at all.
 
Well, the reason why Tesla shouldn't pre-condition the battery before arriving at a SC, is because it uses a LOT of energy. And, some people driving to a SC are at low SOC, and pre-conditioning might make the situation worse. Of course, then the next question is, can't the car tell if you're super low on charge, not to pre-condition automagically? You're right, the car should figure it out.
I have at least 20% SOC at arrival.