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Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

Discussion in 'Model S: Battery & Charging' started by wk057, Feb 2, 2016.

  1. AmpedRealtor

    AmpedRealtor Well-Known Member

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    I don't believe your vehicle is one of the vehicles impacted by the software-induced range loss.
     
    • Informative x 1
  2. DJRas

    DJRas Member

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    Your data shows pretty good degradation. The TMSpy data also shows that they use the "Nominal" fullpack (includes the 4kWh buffer). Their SoC is the nominal remaining divided bybthe nominal full pack. This when you were at or near zero percent usable TMSpy shows 5+%.

    My car prior to 2019.16.1.1 update had similar degradation (about 8%). But now my rated range is 217 miles and Usable full pack of 60.3kWh (23%).

    The original 2014 S85 battery was advertised with EPA rated range of 265 miles at 295Wh/mile. That comes out to a usable 78kWh originally usable.

    At some point Tesla also change the multiplier used to calculate the rated range displayed on our dashboard. The current multiplier is 276Wh/mile.
    I don't have enough data the pinpoint when thst occurred.
     
  3. Blu Zap

    Blu Zap Grinning member

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    That's what I am seeing Full pack is around 60 kWh. I started with a full topped off battery. Finished with 7% remaining having used 58.1 kWh. So lets forget about miles and talk about kWh. It seems like 2019.16.2 reduced kWh. It had been at about 5% degradation previously. Or 73.15 kWh. Now around 60.0 kWh. So about an 18% loss in kWh thanks to 2019.16.2. Sound right?
     
  4. DJRas

    DJRas Member

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    My estimate is 8kWh loss with 2019.16 2.
    247×0.276=68.2 kWh... now 60.3
     
    • Like x 1
  5. wdolson

    wdolson Supporting Member

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    There is a whole thread here on the forum with people complaining about their 90Ds losing range with the update.
     
  6. tomas

    tomas Only partially psycho

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    Important to keep the 16.2 discussion in 16.2 thread. Why?

    1) not everyone affected. My P85 totally unaffected. Keeping it together helps with the sleuth work to figure out how to know if you are affected.

    2) volume of owners (not posts) in that thread influences Tesla to prioritize fix. Shotgun discussion at bottom of years old thread does nothing.

    3) this thread is about delivered hardware capacity. Degradation (real, imagined) and software induced reductions of usable capacity (intentional/permanent or accidental/temporary) are another topic.
     
    • Like x 1
  7. Roadrunner13

    Roadrunner13 Member

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    Very good details!
    Looking both a TM-Spy and your dashboard, the car's BMS 'believes' you have as much as 5% left even if the car is 'unwilling' to use it...possibly because of Group 57 that is out-lyingly low.

    Your 7.3% degradation includes this remaining 5% energy in the battery (which is NOT the brick protection).
    Possibly in ideal conditions and after some magical BMS balancing event, that 5% (or part of it) could become usable again and thus your 'true' degradation would be significantly less than 7.3%...if I'm trying to stay positive.

    Negatively speaking, if it is group 57 that is creating a large portion of your degradation, you may be experiencing further range decrease if this group continues trending down!!!...in which case, maybe you'll be 'lucky' enough to hit Tesla's warranty threashold..
    This graph helps highlighting that Group 57 is an outlier within Tesla's pack and although they don't recognize this data officially, it gives good leverage in your discussions with them if it stays out-of-whack compared with the rest.
     
  8. BigNick

    BigNick Disaffected Member

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    As for the myth about driving the battery to under 10% SOC and AC charging back to 100% to rebalance the cells, over the last week or so I did just that.

    First discharged to 5% SOC, overnight 40A charge to 100%, then down to 4% and back to 100%, then down to 2% and back to 96% where the charger shut off well before reaching 100%.

    The Pack kWh as reported by TM-Spy was 77.3 at the first complete charge, 76.9 at the second, and down to 73.9 at the third!
    9D8DBDDA-4C15-42E2-9F4B-F8E2B000F69B.jpeg

    At this point, I thought I was damaging my pack from multiple charges to 100% despite driving the car within ten minutes or so of completing the charge.

    After I got to work, my Pack was back to 78.2 kWh.
    9888EB75-0D96-4041-AC96-89B411707F73.jpeg

    Basically I have no clue where the Pack number is coming from or how it is calculated. My latest charge (40A to 80%) now shows 77.0 kWh.
    EA1B0B46-303F-42E3-8DF0-4D67EFFFDCD7.jpeg

    Judging by my voltages at my latest charge to 100% (1st image), if I am being limited, it is more of a barbershop shave than a scalping. I won’t be charging to 100% again for quite a while.

    At low SOC, my “57” group still shows a good bit lower than the rest.

    So basically I have no idea what the software is doing to my pack.
     
    • Informative x 1
  9. alloverx

    alloverx Member

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    In the other tread the implication is Tesla tried to fix secret problem X but instead highlighted secret problem Y.
    Perhaps its related to high number of super (fast) charging?
     
    • Like x 1
  10. EV-Tech Exp

    EV-Tech Exp Member

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    United Kingdom

    Really fantastic post; clearly indicates use of simultaneous extended kalman filters for prediction of individual 'brick SoC', which enables adaptive balancing.

    I'm more impressed that the BMS algorithms are so drastically revised via an OTA update!
     

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