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Long Term Battery Life - Input from HK Tesla owners

Discussion in 'Hong Kong' started by gubes, Nov 22, 2015.

  1. gubes

    gubes Member

    Joined:
    Mar 26, 2014
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    Location:
    Hong Kong
    Hi Guys,

    I am trying to figure out what the usual battery degradation is for Tesla batteries in Hong Kong. There was a study done in the US which concluded that the AVERAGE Tesla Roadster's battery retained 80-85% of its original capacity after 100,000 miles (or 160,000 kms).

    Other studies have suggested that a typical Lithium Iron battery degrades to 80% of its original capacity after around 6,000 full charge cycles. So for instance, if you own an 85kWh Model S, with mileage of 220Wh/km, it would imply that you would hit that in over 140,000 miles or over 230,000km. This is based on charge cycles alone (which would be overstating its life) as there are other factors influencing longevity.

    For instance, I discovered that mean temperature actually has a bigger impact on long term battery life than the number of cycles. i.e the lower the temperature, the longer the battery life. (Ironically, the lower the temperature, the worse it is for mileage). Given that HK has a warm climate compared to the USA as a whole, one would expect that the longevity of the battery in HK would be worse.

    Does anyone here own say, a roadster that has done anything close to say, 100k kms to give an indication on how their battery has lasted compared to when it was new? Or anyone who lives in a warm climate?

    Cheers
     
  2. markwj

    markwj Moderator, Asia Pacific

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    Location:
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    I'm at 50,000km on my roadster, almost five years into ownership, and down about 6% from new.

    Tom Saxton, who handled the roadster study, has looked at the data from my different directions (temperature included). I'm sure if you PM him, he can provide his feedback.
     
  3. gubes

    gubes Member

    Joined:
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    Location:
    Hong Kong

    Thanks markwj, that is uesful. 6% after 50k km in Hong Kong seems to be broadly in-line with the US numbers. I assume you have had the car for around 5 years.

    I think that is pretty encouraging. Part of the reason I ask is that at my firm we are having an internal debate as to resale value of EVs in China etc
     
  4. LargeHamCollider

    LargeHamCollider Battery cells != scalable

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    Roadster and MS have different batteries, MS should fair significantly better than the Roadster, most MS owners with 50k km on this forum have well under 6% degradation.
     
  5. Titus

    Titus Member

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    Sep 22, 2015
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    Location:
    Hong Kong SAR
    How do you guys check the battery capacity? Just range calculations or service center does that for you?

    Yea I also wonder about the charge cycles; I remember reading an iPhone article a while ago saying if you keep it above 40% then that's not considered a full drain/charge cycle and can extend your battery life if you never let it drain below 40%. I see a lot of people running their battery down to a few kms of range left and wondered if that reduces capacity more than say if you drive the same 300km but had recharged it twice from 200km?
     
  6. jsiu

    jsiu Member

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    There have been a lot of articles written about batteries. Simply keeping your battery within the range between 30-90% should be fine.
     
  7. Lerxt

    Lerxt Member

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    Elon Musk has previously tweeted that you should keep it between 30-80%.
     
  8. jsiu

    jsiu Member

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    Location:
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    I have no disagreement with Elon Musk. If you charge up to 90%, once you use your car, you will quickly fall in the 30-80% range. This is the reason why Tesla service recommend us to charge the car up to 90% only.
     

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