Thanks. I bought the performance to drive fast so charging lower would definitely not work for me. I've read that all these short trips may impact this somehow. I've put in a ticket with tesla. I don't even drive enough to do a lot of deep discharges. Any other ideas? Showed 260 at 90 percent after the charge. If this keeps up ill probably sell the car while the market is hot. Or maybe im overreacting? Is this range meter dependant on anything other than battery (eg weather driving habits etc)
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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
- Thread starter KK_RedM3
- Start date
AlanSubie4Life
Efficiency Obsessed Member
If you’re never deep discharging it is a lot harder for the BMS to keep a proper estimation. So hard to say whether what you are seeing is real or not.
In the end you at least need to try a bit of a change in habits to see if you get a recovery.
It could well be real (8% loss). But it’s hard to say without investigating.
Tesla will say your battery looks great most likely but you never know.
Per @GigaGrunt’s very well informed post below from early 2020, we’re on at least the 3rd iteration of chemistry for Model 3. How degradation has changed with these iterations is not (publicly) known.
I tried to avoid this rabbit hole but the mobile app shows you miles now. 8 percent in 10 months at 6k miles is beyond unreasonable if true.
AlanSubie4Life
Efficiency Obsessed Member
Yes, there may well have been subtle changes as I said.
However the degree of change required for the 82.1kWh cells probably is at a different level than those prior iterations. Required new cell lines, etc., so more substantial changes would have been possible to bring up off line without fear of disrupting the manufacturing line.
In the end no one outside of Tesla knows how the different generation may behave and we just have to see what the data says.
AlanSubie4Life
Efficiency Obsessed Member
I know people who had that experience with the 2018 generation of cells (and it was real - it hasn’t budged much in the subsequent two years). We have very limited such reports for 2021 vehicles.
Whether you want to investigate is up to you. It seems fine to have Tesla tell you all is well (or not), so your strategy seems fine.
When you say hasn't budged do you mean the range loss continues at a high rate or that it has stayed stable? I mean it it stays at 8 percent ish I suppose I could live with it.
If you need higher SOC for range or performance, use what needed but try to avoid having the car standing for long time with high SOC.
It is the Time x SOC x Temp that cause the most degradation and you can use high SOC, large DOD without causing very high degradation from these conditions.
Use the setting to have the charge to be finished not too long before you leave with the car. Then the car will not have many hours standing with high SOC.
Also, the app in the phone does not show the real full charge range every time, at least it doesnt for me.
Most often it shows a much lower range than the car does at full charge. Some time it show the same number but not that often.
So using the app as a degradation meter is not that good.
Most often it shows a much lower range than the car does at full charge. Some time it show the same number but not that often.
So using the app as a degradation meter is not that good.
AlanSubie4Life
Efficiency Obsessed Member
Yes. On this front, @clerks , you could take a picture of your energy screen as detailed elsewhere (sticky post here). If you post that picture, taken specifically as outlined in that thread, we would be able to see better what the issue is, if any.
Stayed stable. It’s quite common for capacity loss to be initially fast and then slow down a lot.
I add a little to @alansubie4ever’s post:
Calendar aging is highest initially and lessens further on. But it is very dependent on the SOC and temperature.
Of you use low SOC and st low ambient temps it quite quickly revert to a straight line, virtually horizontal. On the other hand, high SOC and high temps will cause a much higher degradation and the leveling out will not occur, and the slope will be clear.
In the picture below 3.45v = about 20-25% SOC. 3.7V = about 50% SOC. 4.1V = about 90% SOC.
If you are at the left picture, 20-25% SOC and 10-25 degrees you start level of after the first 200 days and after 2 years the degradation will be low, onfly a few percent.
If you are at 4.1V/ 90% and 40 degrees you still are going down rapidly after two years.
This picture refers to Panasonic 18650 NCA cells( quite close to Model S and Model 3 for chemistry).
Taken from this very good research report:
https://mediatum.ub.tum.de/doc/1355829/file.pdf
Its way more than 100 pages so its *Battery nerd level reading*
I know which road I would choose, and I have already gone that way, since day one with my M3P
Dave's recent post reminded me that I wanted to ask about this graphic that AAKEE posted. It seems to show a sharp break between aging about 55% and lower, versus aging at 60% and above. The text to the right of the graphic seems to address this a little, but, it's hard to read since it's cut off.
Can anyone explain what is happening in this region?
This is because the main cause of degradation is having a low anode
potential.
Central graphite peak
This ”step” is present in all research reports but in some research it is hidden by the fact that in these tests they setup the tests with few datapoints, for example only measure degradation at 0, 25, 50, 75 and 100% SOC.
The line drawn between the datapoints do not represent the reality and hide the step.
I guess this is deep enough described?
To go deep into this I recommend:
https://iopscience.iop.org/article/10.1149/2.0091701jes
Not that many pages and not too hard to read/understand.(still *Nerd level warning*)
Appreciate the replies. Yeah I would say my car has largely say at 80 ish percent since delivery on average. I live in Pittsburgh so it's not in hot weather all that much. Looks like I need to keep the car at a lower SOC although that's a bummer because it takes away the performance. I'll run the screen test but im a little afraid.I add a little to @alansubie4ever’s post:
Calendar aging is highest initially and lessens further on. But it is very dependent on the SOC and temperature.
Of you use low SOC and st low ambient temps it quite quickly revert to a straight line, virtually horizontal. On the other hand, high SOC and high temps will cause a much higher degradation and the leveling out will not occur, and the slope will be clear.
In the picture below 3.45v = about 20-25% SOC. 3.7V = about 50% SOC. 4.1V = about 90% SOC.
If you are at the left picture, 20-25% SOC and 10-25 degrees you start level of after the first 200 days and after 2 years the degradation will be low, onfly a few percent.
If you are at 4.1V/ 90% and 40 degrees you still are going down rapidly after two years.
View attachment 721847
This picture refers to Panasonic 18650 NCA cells( quite close to Model S and Model 3 for chemistry).
Taken from this very good research report:
https://mediatum.ub.tum.de/doc/1355829/file.pdf
Its way more than 100 pages so its *Battery nerd level reading*
I know which road I would choose, and I have already gone that way, since day one with my M3P
New question - will modifications to the car affect the screen calculation? I am running wider 20s, lowering springs, a front splitter and wheel spacers. As a result of these modifications I regularly get lower range than projected. I assume those are affecting my average consumption calculations? If so wouldn't that alter the calculation? Edit and mudflaps
No. The remaining range estimate is not a guess-o-meter like other manufacturers.
Thanks. I probably wasn't clear. Not referring to the range estimator at the top left. I am referring to the energy app, consunption tab and the references to historical avg wh/mi and projected range. My car requires more wh/mi because of these modifications so wouldn't that throw off the calculation of projected range?
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