Cannot set max charging threshold below 50%

[ewoodrick]

There is a very good match between the general tests of for example Panasonic cells with NCA chemistry and the Panasonic cells Tesla use.

Actual Tesla model 3 cells. Only three test points but if you take these and overlay on the multi point tests you get a descent match.

Actual Tesla model S cells calendar aged:


These arecells taken out of almost brand new Teslas.

Here’s the sum of the research data set as the blue line, for my MSP’s average cell temp and the amber line is the monthly Nominal Full Pack. So far a very good match.
(I made the same for my M3P 21 during 2.5 years and it was a very good match as well.



I find it slightly interresting that people driving EV’s and that have at least slight interrest in EV technology which to a very high level is built on research,
does’nt accept the research about lithium batteries

That wasn't so hard was it.

So, to summarize, we're are only talking about 3, maybe 4% differential in initial decline. And none of the testing seems to be long enough to measure the much more important period of stability after the initial degradation.

Aren't we talking about similar differences when we talk about the wheel covers on and off with a Model 3?

Our Testing Shows Tesla Model 3 Aero Wheel Covers Really Do Improve Efficiency

In our testing, they proved their worth by yielding up to 10 additional miles of range.

www.caranddriver.com

 

[AAKEE]

That wasn't so hard was it.

I think I did post both those charts before in threads where you took part?

So, to summarize, we're are only talking about 3, maybe 4% differential in initial decline.

Mostly around 5-5.5% for the first year for panasonic NCA, for the most common temperatures and SOC levels used.

And none of the testing seems to be long enough to measure the much more important period of stability after the initial degradation.

We do not really have a period ofstabimity like that. The capacity declines slower a d slower from calendar aging.

The researchers are agreeing very well on that the calendar aging is reducing the rate with the square root of time.
Except from that testing shows this, the fact that the solid electrolyte interphase (SEI) that is a part of calendar aging and also acts as a protection against further losses would matematically end up in the square root principle.

A lot of the results also shows square root dependance, so we do not need to be unsure of this.
There also is tests for, for example 3 years, showing that long time calendar aging matches the short tests.

We can take a 5 or 6 year old Tesla model 3 as sn example, calculating the approximate degradation and it will match quite well. If the test data was not valid, we would not have a match.
Using the test data on my 2021 M3P with the new 2170L cell matched.
Using it on my 2023 Plaid, matches so far.

There is simply no way around the fact about how calendar aging works.

 

[ewoodrick]

I think I did post both those charts before in threads where you took part?

Mostly around 5-5.5% for the first year for panasonic NCA, for the most common temperatures and SOC levels used.



We do not really have a period ofstabimity like that. The capacity declines slower a d slower from calendar aging.

The researchers are agreeing very well on that the calendar aging is reducing the rate with the square root of time.
Except from that testing shows this, the fact that the solid electrolyte interphase (SEI) that is a part of calendar aging and also acts as a protection against further losses would matematically end up in the square root principle.

A lot of the results also shows square root dependance, so we do not need to be unsure of this.
There also is tests for, for example 3 years, showing that long time calendar aging matches the short tests.

We can take a 5 or 6 year old Tesla model 3 as sn example, calculating the approximate degradation and it will match quite well. If the test data was not valid, we would not have a match.
Using the test data on my 2021 M3P with the new 2170L cell matched.
Using it on my 2023 Plaid, matches so far.

There is simply no way around the fact about how calendar aging works.

You then do agree that it is not much different than wheel covers?

And yes, you can't get around calendar aging, pretty much my exact point. (I'm not talking about differing SoC aging)
As is shown in the second set of graph posts, the Figure 4.5,
6% of the aging comes from age. The worst case was only down about 3% below that.

Again, 3% is the same as taking the wheel covers off the car!!!

And most people don't care about this little range difference in the wheel covers.

 

[AAKEE]

You then do agree that it is not much different than wheel covers?

And yes, you can't get around calendar aging, pretty much my exact point. (I'm not talking about differing SoC aging)
As is shown in the second set of graph posts, the Figure 4.5,
6% of the aging comes from age. The worst case was only down about 3% below that.

Again, 3% is the same as taking the wheel covers off the car!!!

And most people don't care about this little range difference in the wheel covers.

Would a five year calendar aging chart do it?

You would need to understand the difference between 3% consumption ( wich is the same each year or day and a degradation rate ut in half.

3% the first year makes 8.5% calendar aging after 8 years.
6% the first makes 17% calendar aging after eight years.
Besides almost 10% better capacity, at arpund 20% the batteries can start to behave unpredictable. That’s where the insdustry consider lithium ion batteeies consumed. That is for a good reason.

So hitting 17% and adding a little for cycles and supercharging we might have cells that are close to end of life.

Reaching 8.5% means we still have much room for cyclic aging and supercharging and still for extended life beyond 8 years.

This is a long time (5 year) calendar aging test with Samsung INR18650 NCA-cells.
Not very high resolution but we can see the square root of time dpendency.

U1 = 80% SOC
U2 = 59% SOC
U3 = 45% SOC
U4 = 28% SOC
U5 = 25% SOC

https://www.researchgate.net/journa...FkIiwicHJldmlvdXNQYWdlIjoicHVibGljYXRpb24ifX0

 

[Leftlane22]

Way too much thinking and talking on this specific topic. Just set to charge to 50% and move on with life. I charge to 80% almost every day, and to 100% overnight when I’m hitting the road. I also supercharge whenever I have to and don’t worry about it for 1 second. I’m sure I’ll trade up way before my battery usage becomes a problem, if it ever does.

 

[AAKEE]

You then do agree that it is not much different than wheel covers?

And yes, you can't get around calendar aging, pretty much my exact point. (I'm not talking about differing SoC aging)
As is shown in the second set of graph posts, the Figure 4.5,
6% of the aging comes from age. The worst case was only down about 3% below that.

Again, 3% is the same as taking the wheel covers off the car!!!

And most people don't care about this little range difference in the wheel covers.

This is my M3P 2021 vs other M3P’s 2021:

New range was 507km/315 mi.

My last full charge after 66K km and 2.5 years was 492km, when driving to sell it.
The average range for the fleet jumped up and down around 460-465km, so lets say 462.5km avg fleet range.

My car had lost 13km or 2.5%
The average car had lost 44.5km or 8.8%
The difference was 6.3% after 2.5 years.
This difference would increase with time.

 

[ucmndd]

If batteries were batteries, then how come the early Tesla and Leaf batteries had such terrible lifespans?

Early Tesla cells had no such “terrible lifespan”. Where did you manifest that from? Many early packs failed due to other manufacturing issues like moisture intrusion and supporting electronics, but the cells themselves were actually quite healthy and long-lived.

Early Leafs are actually a perfect example of what bears out in @AAKEE ‘s graphs. They had terrible thermal management and were small packs, thus generally needed to be charged regularly to very high states of charge. As a result they degraded very quickly, particularly in hot climates (i.e. exactly what is depicted in the charts that you seemingly disagree with for reasons unknown).

 

[bmah]

So I know that details of battery management are a favorite topic among some of us Tesla owners, but for the benefit of OP:

@MichaelSte2022, you don't need to understand all of this to enjoy the car. Charge it enough to make sure you don't run out of battery and strand yourself somewhere. Beyond that, just drive it and don't overthink the charging.

Bruce.

 

[MichaelSte2022]

So I know that details of battery management are a favorite topic among some of us Tesla owners, but for the benefit of OP:

@MichaelSte2022, you don't need to understand all of this to enjoy the car. Charge it enough to make sure you don't run out of battery and strand yourself somewhere. Beyond that, just drive it and don't overthink the charging.

Bruce.

Thank you for that input Bruce.

 

[tzgator]

WRT Nissan Leaf Batteries, they are air cooled and smaller capacity on average, and so would often get DC Fast Charged >1 time per day, in high ambient temperatures. This led to some shorter lifespans of the packs.

All the Tesla batteries are liquid cooled and have much better thermal management of the packs.

 

[MichaelSte2022]

WRT Nissan Leaf Batteries, they are air cooled and smaller capacity on average, and so would often get DC Fast Charged >1 time per day, in high ambient temperatures. This led to some shorter lifespans of the packs.

All the Tesla batteries are liquid cooled and have much better thermal management of the packs.

Makes sense. But you saved tons of money over a Tesla so still a huge win for you, financially speaking.

 

[ewoodrick]

Early Tesla cells had no such “terrible lifespan”. Where did you manifest that from? Many early packs failed due to other manufacturing issues like moisture intrusion and supporting electronics, but the cells themselves were actually quite healthy and long-lived.

Early Leafs are actually a perfect example of what bears out in @AAKEE ‘s graphs. They had terrible thermal management and were small packs, thus generally needed to be charged regularly to very high states of charge. As a result they degraded very quickly, particularly in hot climates (i.e. exactly what is depicted in the charts that you seemingly disagree with for reasons unknown).

So why did so many pre 2016 battery packs have to be replaced? It's a well-known issue.

Nissan fixed the Leaf problem by reformulating the batteries, not by adding thermal management.

Nissan and Tesla seemed to fix their issues about the same time and since then battery reliability has been significantly higher.

Oh, I had two Leafs, I'm intimately familiar with the issues.

 

[AAKEE]

So why did so many pre 2016 battery packs have to be replaced? It's a well-known issue.

Nissan fixed the Leaf problem by reformulating the batteries, not by adding thermal management.

Nissan and Tesla seemed to fix their issues about the same time and since then battery reliability has been significantly higher.

Oh, I had two Leafs, I'm intimately familiar with the issues.

The majority of the tesla packs was not tired cells.
It has been water intrusion, loose cables and broken BMB’s etc.

 

[ewoodrick]

WRT Nissan Leaf Batteries, they are air cooled and smaller capacity on average, and so would often get DC Fast Charged >1 time per day, in high ambient temperatures. This led to some shorter lifespans of the packs.

All the Tesla batteries are liquid cooled and have much better thermal management of the packs.

You do realize how fast CHAdeMO chargers are, don't you? Only 50kW.
I don't think that most get fast charged, there weren't that many DCFCs around. Actually a large number of Leafs didn't even have DCFC capability. CHAdeMO was an extra cost. Quite a few ONLY had J-1772 connectors.

The problem manifested itself in Arizona, where there were really hot temperatures occurring. It was not prevalent in the remainder of the country.
Nissan recognized the issue, went back to the drawing board, reformulated the batteries and resolved the issue.

 

[ucmndd]

So why did so many pre 2016 battery packs have to be replaced? It's a well-known issue.

Did you read my post?

Nissan fixed the Leaf problem by reformulating the batteries, not by adding thermal management.

Do you have any evidence to support this? Everything I can see suggests that improvements in gen2 were almost exclusively related to thermal management improvements, not a fundamental change in cell chemistry.

 

[ewoodrick]

Did you read my post?


Do you have any evidence to support this? Everything I can see suggests that improvements in gen2 were almost exclusively related to thermal management improvements, not a fundamental change in cell chemistry.

Yes, I read your post.

Here's one example from A look at Tesla battery degradation and replacement after 400,000 miles
"Tesla has changed the chemistry when upgrading its battery pack to 90 kWh and there are rumors that the new chemistry resulted in the accelerated capacity degradation."

Another article talking about chemistry changes https://seekingalpha.com/article/4001134-tesla-already
Tesla was already changing chemistries to better manage supply chain Breakdown of raw materials in Tesla's batteries and possible bottlenecks


As to the Leaf, let me put it this way, they didn't change the pack, they didn't add thermal management. Even my 2018 redesigned Leaf still had air-cooled batteries and it ran and charged great!