Reducing degradation stress - a tale of three batteries.

[MY-Y]

After careful observation of countless posts on battery degradation, and how concern about this can take away some of the joy of Tesla ownership...

Consider these three scenarios:

Scenario 1: Larry, whose 2020 MY AWD is doing terrible...

In 6000 miles, his battery range has plummeted. He's asked Tesla and they say nothing is wrong. What should he do? Clearly, his battery has a problem! See how he's dropped from 316 miles to 288 is just 7000 miles! He charges to 80% and has tried deep cycling, letting his car sleep, all of the suggestions. He's in the bottom 5% of TeslaFi.

Scenario 2: Moe, whose 2020 MY AWD is the same age and model as Larry's, but has stayed below avarage for the past 15,000 miles. The good news is that there has been nearly no degradation for almost a year. Moe treats his battery about the same as Larry. When asked how he has had no degradation for 15k miles, Moe says he does nothing special. Charge to 80% daily, occasionally charge to 100% for trips, and try to let the car sleep at work.

Scenario 3: Curly. It seems that Curly has found the magic steps for battery health. He is happy to report that for the last 10k miles, he has watched his MY climb from the bottom (dead last) car on TeslaFi to one of the top performers. His range climbed from a meager 285 to a strong 305! Many want to know what He did so they can get the same great results.

So, how can our three scenarios have such different results???

I posted this to help others avoid the stress of tracking and worrying about battery degradation. The difference on these three scenarios is just time. They are all from my car, with no difference between these other than time. The lesson here is that the BMS doesn't represent battery health well. The algorithm is wonky, so just ignore it and enjoy the car!

 

[Casss]

This is the most eloquent, well written (and presumably time consuming) takedown of someone’s wonky code I’ve seen in a long time and I love it

 

[Whiskeypapa]

After careful observation of countless posts on battery degradation, and how concern about this can take away some of the joy of Tesla ownership...

Consider these three scenarios:

Scenario 1: Larry, whose 2020 MY AWD is doing terrible...

In 6000 miles, his battery range has plummeted. He's asked Tesla and they say nothing is wrong. What should he do? Clearly, his battery has a problem! See how he's dropped from 316 miles to 288 is just 7000 miles! He charges to 80% and has tried deep cycling, letting his car sleep, all of the suggestions. He's in the bottom 5% of TeslaFi.
View attachment 804210

Scenario 2: Moe, whose 2020 MY AWD is the same age and model as Larry's, but has stayed below avarage for the past 15,000 miles. The good news is that there has been nearly no degradation for almost a year. Moe treats his battery about the same as Larry. When asked how he has had no degradation for 15k miles, Moe says he does nothing special. Charge to 80% daily, occasionally charge to 100% for trips, and try to let the car sleep at work.
View attachment 804212

Scenario 3: Curly. It seems that Curly has found the magic steps for battery health. He is happy to report that for the last 10k miles, he has watched his MY climb from the bottom (dead last) car on TeslaFi to one of the top performers. His range climbed from a meager 285 to a strong 305! Many want to know what He did so they can get the same great results.
View attachment 804214

So, how can our three scenarios have such different results???

I posted this to help others avoid the stress of tracking and worrying about battery degradation. The difference on these three scenarios is just time. They are all from my car, with no difference between these other than time. The lesson here is that the BMS doesn't represent battery health well. The algorithm is wonky, so just ignore it and enjoy the car!
View attachment 804220

I’ve always been a big fan of your three test drivers (nyuck, nyuck, nyuck)!

 

[jcanoe]

It is interesting that peak battery capacity for the OP's 2020 MY appears to coincide with springtime, warmer temperatures. This is not true for 2021 when there is no peak. This could be due to a different driving pattern, i.e. many short trips or not enough data for the algorithm.

 

[Dennisis]

Thanks for sharing. Mine shows a similar trend over 2 years and 19K, all good .

 

[Robipad]

Since observing my battery degradation in Teslafi I decided to do a BMS calibration 2 times in a row. It resulted in taking away all my worries. Just listen to:

I bought my Tesla model 3 DM in februari 2019, started with Teslafi at about 3000 km. Supercharged almost all the time up to 90% for one year (close to me and free of charge for that periode). Then started charging at home at 11 kWatt up to 90% almost the the time. Then started to worry since it came below the avarage degradation curve. The last 2 tops in front of the line 2022 show the calibration moments.

 

[DownshiftDre]

Would be interesting to have miles vs time plot to see if rate of change in miles has any affect on what the calibration does.

 

[MY-Y]

It's pretty steady - about 1200 miles per month.

 

[sleepydoc]

View attachment 804469
Thanks for sharing. Mine shows a similar trend over 2 years and 19K, all good .

Clearly your battery got Covid between 5000 and 10000 miles but has started to recover!

 

[scottf200]

Scenario 3: Curly. It seems that Curly has found the magic steps for battery health. He is happy to report that for the last 10k miles, he has watched his MY climb from the bottom (dead last) car on TeslaFi to one of the top performers. His range climbed from a meager 285 to a strong 305! Many want to know what He did so they can get the same great results.
View attachment 804214

Did this 3rd scenario show up after 2021.44.XX.Y ?

From another post I did:

Anyone else seeing 2021.44.* Firmware Version ranges raise mileage estimates? Charging methods and weekday range of 80 to 30 to 80 ... are the same.
Top graph below is from the Google sheet chart and the lower corresponding (purple line focus cone) is the corresponding data in the TeslaFI battery chart.
In below top chart, the [Col C sheet] or "FV +200" chart legend and blue vert lines in top chart values would be a value of
244 and equate to 2021.44.XX.Y (200+44)
232 and equate to 2021.32.XX.Y (200+32)
with the reason to quickly put it on the same scale as the mileage range.

 

[MY-Y]

I'm on the FSD beta branch, so my version numbers are different. My range increase started on 11/9. It doesn't seem directly correlated with any particular software drop.

It has dropped back down to 299 over the past couple of weeks. I haven't let it sleep at any level but ~60% and 80% for a while. I'll have it sleep as a couple of different SoC levels to see what the BMS does. (Not that it really matters.)