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New S60 battery degradation thoughts

Discussion in 'Model S: Battery & Charging' started by gabeincal, Apr 6, 2017.

  1. gabeincal

    gabeincal Enjoying Napa life the electric way

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    IF and only IF the current S60 (75 limited to 60) batteries degrade, does Tesla have a contractual or goodwill reason to avoid this degradation?

    See technically, since the 60 is a 75 battery, there is no reason that the 60 capacity should start losing any miles before it lost almost 15kWh down from the 75. But if it does, then Tesla is basically not doing a goodwill effort to the 60 owners despite the fact that they COULD do it.

    My problem is this: degradation is a physical property that is given. There is not a lot we can do about it and therefore it is widely accepted. However, in the case of software limited batteries (60, 70 and maybe some 85's?), Tesla could do battery management tricks to avoid this degradation for many many years. If they don't then they're basically enforcing a physical property that needn't be affecting these users and I can see how (if it got bad) they could be taken to court for not acting faithfully towards these owners.

    What do you guys think?
     
  2. azred

    azred Member

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    I think you are overthinking the situation.
     
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  3. jelloslug

    jelloslug Active Member

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    I'm not worrying about it.
     
  4. gabeincal

    gabeincal Enjoying Napa life the electric way

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    I agree :) it's more a theoretical brainstorming thing than anything else...
     
  5. chillaban

    chillaban Active Member

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    So I'm just about to trade in my S70D (locked S75D), after 18,000 wonderful miles in a little over half a year….

    It started out charging to 236-237 miles at 100%, but now it charges to 228. I've only occasionally used 100% charges for starting trips and never left it over 90% for more than 8 hours.

    So I can tell you, for sure, the degradation is exposed even if you are locked to a lower capacity. If there's 96% of the battery available, you will get 96% of the original rated capacity for your trim.


    (FWIW, I agree that it feels a little gross that Tesla could offer me 239 miles still, but they won't. But at the same time, it'd make the 60->75 or 70->75 upgrade dumb and pointless if it's just going to be gone in a year or two).
     
  6. gabeincal

    gabeincal Enjoying Napa life the electric way

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    Thanks for this, exactly what I was looking for... So they do percentage of remaining capacity to be available rather than a fix capacity...

    Yeah it does feel wrong because this way degradation is not eating into their profit that much and it's just sad to see that they prioritize profit over the happiness of the owners...
     
    • Disagree x 3
  7. diesel

    diesel Member

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    You didn't pay for that battery capacity and the benefits it provides. Not sure why you feel entitled to it.
     
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  8. chillaban

    chillaban Active Member

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    I also think what Tesla is doing is fair from a business standpoint. I think it's an acceptable compromise of the possible ways they could've implemented software limited battery capacity.
     
  9. gaswalla

    gaswalla P4201/85/airsusp/pano/19i

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    You will see degradation, just less since it's never charged to 100%. You bought 80% of a 75kwh battery and there will be some degradation, but as folks have learned, Tesla batteries degrade minimally. As 80% of that battery changes in capacity over time, that's what you'll have.
     
  10. brkaus

    brkaus Active Member

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    It is "fair" to allow the degradation to scale with the overall degradation.
     
  11. tpham07

    tpham07 Member

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    I read somewhere all tesla batteries degrade 5% within the first 50k miles but then between the next 50k-500k miles you only see another 5% degradation on average. Unless you're flooring your car or draining the battery on a daily basis i think the battery will outlast the car.
     
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  12. chillaban

    chillaban Active Member

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    Well the range looks anywhere from 2% to 10% when I looked at the previous data. And some of that is luck-of-the-draw, not just owner usage/abuse patterns.

    But degradation is important to keep in mind if your travel patterns strongly depend on your car getting close to advertised range. 5% could be a nontrivial number of miles.
     
  13. tchockie

    tchockie Member

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    i really love how this forum is filled with nerds and dreamers more so than any other forum ever.

    i'm charging mine from ~20% to 100% every day, so i guess we'll find out how it does in a few years..
     
  14. chillaban

    chillaban Active Member

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    To be fair, while some dreams are out of the question, others are not as clean cut. Take my situation: I had a software locked 70D delivered with 236 miles. Which is below the EPA rated mileage, which is based off an average between the 90 and 100% charge anyway. They explained that the underlying 75kWh battery pack, with normal manufacturing variance, has less capacity than others, and that as a result my locked capacity is also lower.

    It's one thing if the pack degraded because of my charging or using habits. But to start out of the gate with a lower capacity despite the ability to provide me more, I think that's a bit evil. IMO they should at least trim the available capacity of the 60D/70D to the value on the window sticker that the EPA certified.
     
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