Thank you for the possibility, but I bought the car used, so I don't know how it was handled in the majority of its life...
Comparing it to the teslafi fleet data, the car is still within normal range after the "decrease".
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determining the battery SOH trends
- Thread starter bumcurriculum
- Start date
Comparing it to the teslafi fleet data, the car is still within normal range after the "decrease".
It is a 2018 Model S 100D, imported last december from the Netherlands with 200 000km on the clock. Since then I use it in Hungary, milage is now at 222 000km.
Thank you!
I do not have the charging constants or the full range on this car, so there might be an alternate way to calculate the capacity.
Do you know if it has the stock battery?
A quick calc in the mobile says around 12% degradation (Guessing the normal charging level that was used and I guesstimate the average temp in the Netherlands).
Range problably dropped less, as there normally is a degradation treshold from the full capacity, hiding slight degradation when looking at the full new range.
Initial capacity was around 101-102 kWh in the 100 pack. These cars delivered ~ 100.5 kWh or so in the EPA test.
12% degradation set the remaining capacity at 88-89 kWh or so.
I guess you can perform the energy grapg calculation in the car.
Picture from a Model 3 P but same calccis valid: average x calculated range x 100/ SOC % = Watt hours.
The setting down right need to be at normal range.
Which tells us that, most probably the car was charged like most people do and the degradation is like most cars will have.
This also tells us that the BMS *most probably is about right on track showing 89.5kWh and that *most probably* there is no displayed range to gain with a BMS calibration.
You’re all set. Everything is just as expected, and fine!
The only thing which is not ideal the wild fluctuations of SoC in the low range. Which is unfortunate on road trips when ideally the car should be discharged to around 10% for the fastest overall trip time.Which tells us that, most probably the car was charged like most people do and the degradation is like most cars will have.
This also tells us that the BMS *most probably is about right on track showing 89.5kWh and that *most probably* there is no displayed range to gain with a BMS calibration.
You’re all set. Everything is just as expected, and fine!
I try to keep following the BMS calibration pattern, and see what happens.
“Jumps” in SOC could possibly also come from that the cell voltage vs real SOC has changed some how. I know supercharging can do this.
I think I wrote about the SOC adjust after droves before. It need to be consistent to come from a over- or underestimate.
It might be possible for the car to learn the new voltage curve by doijg BMS Calibs, I do not know about that.
There also is a BMS reset in the service menue that *might* be able to learn the SOC vs voltage curve better. I do not know this but it would be possible to create such a function.
Since I do this 100/90% to <20% SoC cycles with lots of sleeps, what I tend to see is that at higher SoC after a sleep the SoC increases, and at lower SoC, the SoC decreases. (the border between high and low is somewhere around 40%). At around 10% this decrease can be quite dramatic (8%->0%)
(just as a fun fact )
I'll try to keep doing this and see if there is any trend of after sleep SoC changes getting smaller in the whole SoC range.
(just as a fun fact
)I'll try to keep doing this and see if there is any trend of after sleep SoC changes getting smaller in the whole SoC range.
zoomer0056
Active Member
Do you have a lot of supercharging sessions?Since I do this 100/90% to <20% SoC cycles with lots of sleeps, what I tend to see is that at higher SoC after a sleep the SoC increases, and at lower SoC, the SoC decreases. (the border between high and low is somewhere around 40%). At around 10% this decrease can be quite dramatic (8%->0%)
(just as a fun fact
I'll try to keep doing this and see if there is any trend of after sleep SoC changes getting smaller in the whole SoC range.
There is information from research about how the Open Circuit Voltage changes after extensive Fast charging. From my memory the OCV increased over 60-80% or so for the same SOC. Didn’t find the picture or report now, but I might.
Theres one issue with Tessie, or maybe a few.
1) There was never a battery with 96.2kWh for the Model S Palladium. The batteries are 99.4 kWh Full Pack When New and delivered 99.3/99.4kWh for the plaid and 98.X for the S LR.
Your capacity loss is not 3.1% but 6.2%.
My plaid topped 98.4 kWh full pack when new and 99.0 kWh nominal remaining.
15 months after my car was built it still has 97 kWh nominal full pack, and last full chsrge was 97.6kWh.
So, by Tessies calculation my battery is about 1-1.5 % better than new.
For @bumcurriculum Tessie will not help for anything.
If the SOC jumps, Tessie can not help that.
Also, Tessie builds it case on OTA data, which has its limits. Thats probably why Tessie use a faulty new value on the pack.
As we know the EPA tests showed 98.X to 100 kWh (in the X test), we know that 96.2 is a bery much understated number, causing the degradation to look much better than it really is.
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