Ahh, I had 50/50 picking the right onethe teslalogger chart
Teslalogger:
X-axis = The Odometer of the car in km.
Y-axis = Indicated range at 100% in km, calculated by actual range/ SOC
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Ahh, I had 50/50 picking the right onethe teslalogger chart
You can also look at @Baluchi’s good post / update of the degradstion after about 23 months: Model 3 SR+ LFP Battery Range, Degradation, etc Discussion@AAKEE does a LFP battery have less calendar ageing than a NCA/NCM battery?
AKA RideshareParticularly considering these are mostly ‘professional’ drivers who likely charge to 100% daily and supercharge often
That’s such a dicey graph eh, hard to figure out exactly what is going on there. However from a real life example, Model 3 LFP showing 424km indicated range when new, now showing 403km after 230,000km, that would still roughly correlate with the lowest dark ‘smudge’ in that graph - from just over 420 to around 405 now for most cars. (albeit with average mileage much lower at between 20,000 and 60,000km)Teslaloggers data show a little bit higher loss than 5% range.
Still to the absolute most extent calendar aging as you say. (Which also is the case for most other Teslas, except the ones covering very long distances each year)
Teslalogger’s average that is noisy from different battery or wheel selection removed and a new line drawn by me.
View attachment 962929
Calendar ageing is a fact of life. Nothing is immortalthe conclusion that displayed range seemed to only be affected by the age of the car -
Yes I agree with that, just wondering if the displayed range at 100% could just be being gradually reduced by Tesla based on the age of the car and no other factors. It’s not like the car is doing a full battery test on itself is it. How does it know the battery degradation? The range is so wildly inaccurate & optimistic anyway there would be plenty of margin for them to reduce range based on a set of pre decided age related milestones and no one is really going to notice.
The displayed range is called "Rated range". This is total battery capacity divided by a hardcoded efficiency value - different for S3XY. It is based in some way to the EPA method of calculating range.displayed range
What’s the BMS going to learn from measuring voltage on an LFP pack lol. When you consider that it’s guessing the SOC most of the time, I’m slightly dubious about its ability to magically measure degradation. I still think my theory has merit - until someone with a larger brain and/or better knowledge convinces me otherwise!Yes the BMS actually monitors the battery. While the car is asleep with no battery usage it will actually measure an open circuit voltage a few times.
That's a good point. I stopped worrying about my battery health with my MY NCA battery after realizing the BMS doesn't accurately measure degradation on it. It's even harder for the LFP BMS. For more details on my NCA thoughts, see: Reducing degradation stress - a tale of three batteries.What’s the BMS going to learn from measuring voltage on an LFP pack lol. When you consider that it’s guessing the SOC most of the time, I’m slightly dubious about its ability to magically measure degradation. I still think my theory has merit - until someone with a larger brain and/or better knowledge convinces me otherwise!
It is a valid question and I actually asked the same, and questioned that the BMS might not be able to estinate the capacity that exact.Yes I agree with that, just wondering if the displayed range at 100% could just be being gradually reduced by Tesla based on the age of the car and no other factors. It’s not like the car is doing a full battery test on itself is it. How does it know the battery degradation?
The range is so wildly inaccurate & optimistic anyway there would be plenty of margin for them to reduce range based on a set of pre decided age related milestones and no one is really going to notice.
Thanks for the explanation! I reckon I looked at a few hundred posts with mileage, age and range at 100% on LFP cars. They all pretty much aligned on age only. So either LFP packs are proving very robust or the reduction in displayed range is purely age based.In a regular Tesla, the BMS estimate a number of kWh to complete the charge
( target SOC - actual SOC) x estimated capacity).
When the charge is complete the real SOC is measured, and if the real SOC is less then the target, the estimated capacity is to low.
If the real SOC is higher than the target the estimated capacity is too high.
With LFP, if the SOC is hard to detect precisely the estimated capacity would be non precise.
I got a message yeaterday from a guy that bought a LFP car to cover daily long trips.
That’s interesting. In my MY RWD group (LFP) there are people who go below 0% - one guy had a pic of the display actually showing minus 11%! They reckon there’s a good 20 or 30km at least below 0% on MY RWD LFP. (When new at least lol). Maybe the smaller packs have less ‘buffer’ at the bottom.(Hes M3P had lost quite much capacity from very large cycles, so he got a LFP to be able to cover 100-0% daily).
Now he had stranded a couple of km from home with 8 km driven past 0%/0km. I take it as it was a very gentle drive below 0.
The car is charged full 4-5 time a week and was charged full tha day of this drive.
Most probably the BMS has overestimated the capacity by 4.5% - the 8 km drive (perhaps maximum 1-2%) = about 2.5-3.5% overestimation.
The car showed 417 km before the drive of the day.
That's interesting indeed. I had thought that the display SoC never goes below 0%, but the trip SoC on arrival estimate does and that's how people are able to determine when they're below 0%.That’s interesting. In my MY RWD group (LFP) there are people who go below 0% - one guy had a pic of the display actually showing minus 11%! They reckon there’s a good 20 or 30km at least below 0% on MY RWD LFP. (When new at least lol). Maybe the smaller packs have less ‘buffer’ at the bottom.
Strange.That’s interesting. In my MY RWD group (LFP) there are people who go below 0% - one guy had a pic of the display actually showing minus 11%! They reckon there’s a good 20 or 30km at least below 0% on MY RWD LFP. (When new at least lol). Maybe the smaller packs have less ‘buffer’ at the bottom.