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teslafi battery degredation report

Discussion in 'Model S: Battery & Charging' started by SSonnentag, May 2, 2018.

  1. SSonnentag

    SSonnentag Active Member

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    I see there are new stats an a graph available with teslafi now. I'm curious as to how accurate this looks for some of you long-time users of the service.
     
  2. Zextraterrestrial

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    #2 Zextraterrestrial, May 2, 2018
    Last edited: May 2, 2018
    seems reasonable except for the 'trend line'

    >85% charges
    Capture.JPG

    >50% Charges
    Capture.JPG

    & this is just looking at the max range in the Teslafi data(started using it 11/16)
    upload_2018-5-2_15-6-22.png
     
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  3. SSonnentag

    SSonnentag Active Member

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    Yeah, I see the same thing with my trend line, although I only have a few months worth of data to work with. I put the data into Excel and used its trend line, which fits the data better, but doesn't necessarily reflect reality either. :D

    teslafi.png



    Here is the Excel graph with trend line:
    excel.png
     
  4. jdw

    jdw Supporting Member

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    I had one range mode charge in the mix, which became my "high range". This created the slope line showing degradation that isn't really there ...it would be good if you could select or filter the charges you wanted to include to omit range charges and also to select charges that were exactly 90% instead of 90% or above.
     
  5. milleron

    milleron Member

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    The Teslafi guys are data gurus, but the average lines do look funny. My "high vs low" drop was 1.7%, but the "high vs current" was 0.0%. I've had the car less than a year, and I suspect the "high vs low" is reflecting a difference in ambient temperatures over the winter (and much-colder-than-average March and April) more than actual battery degradation. Now that we finally are seeing some near-average spring temps, my range at 60% charge is exactly where it was when the car was new, early last summer. Because of seasonal variations, I don't think these degradation numbers will be very meaningful until a car has a couple of years of data points.
     
  6. barjohn

    barjohn Member

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    If you have more than one Tesla it combines the data into one line. It doesn't separate the data by vehicle.
     
  7. PacManMX

    PacManMX Member

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    D88479C7-0363-45B1-BBDD-E21F59BE9E44.jpeg Attached is my report. ~22 months of data for my 75 X. 20k miles. The slope at ~15 months in is consistent with me thinking “oh, this latest update is more aggressive with long term battery protection and that’s why Tesla is decreasing my capacity”. It does also coincide with winter but 1) my car is garaged and my garage temp is fairly consistent year round and 2) this past month has been unseasonable warm and there has been no change.
     
  8. skitch23

    skitch23 Member

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    My car was a CPO and it was in service for 41 months prior to me owning it. I know I'm not anywhere close to qualifying, but at what point does Tesla say a battery is in need of a warranty replacement vs it being "normal degradation"? 11 miles in a little over a year is more than I would have hoped to see.... especially since it hadn't lost that much in the nearly 3.5yrs combined before I got it. I mean, hell, at this rate in two more years, I'll be struggling to drive to/from CA without more SC's being installed in AZ.

    Capture.PNG
     
  9. animorph

    animorph Active Member

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    Mine has a big step down from when 17.26.76 (I think) changed the Wh/mile constant. I'd need some kind of correction for that. The trendline looks reasonable on mine.
     
  10. Snowstorm

    Snowstorm Active Member

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    Mine says I have lost about 3% in year 1 and I absolutely baby the battery. No 100% charge, 70-40 usage range nearly all the time. I don’t know if the estimate is fully accurate unless you actually do 100% charge and deep discharge to check.
     
  11. Zextraterrestrial

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    The max range is very dependent on temperature. I am in an area that is mostly 50-70F year round. The data points that are at 80-90 all show 252-3 rated(>90 254) where around 50-60 it is 249-50. @ 30F 247
     
  12. David99

    David99 Active Member

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    The warranty does not cover degradation. It's up to them to give you a replacement battery or not. A few people got one (you don't get a new one, you get one that has the same or better range) but they had more serious issues. Other than Tesloop, I don't know anyone that got a replacement battery due to degradation
     
  13. skitch23

    skitch23 Member

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    I know it doesn't cover degradation. That wasn't what I was asking. At what point does Tesla consider it to be a problem with the battery and NOT normal degradation.
     
  14. Tozz

    Tozz Active Member

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    It could also be lack of balancing instead of degradation. Charge to 100% and try to run it down to 0% or close to 0%. That will re-balance the pack and might result in more miles..
     
  15. branndonbriggs

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    Has anyone had a percent gain since their starting range? This is over roughly 14,000 miles.[​IMG]
     

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  16. jdw

    jdw Supporting Member

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    Yup, I've been lucky enough to gain range over 3 years/40000km (24000 miles), going from 267 miles to 270 (85D). It's only begun dropping a little bit lately, I'll see whether I recover over the summer.


    Screen Shot 2018-06-30 at 1.33.38 AM.png Screen Shot 2018-06-30 at 1.36.14 AM.png
     

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