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Charge level

Discussion in 'Model S: Battery & Charging' started by steilkurve, May 25, 2015.

  1. steilkurve

    steilkurve Member

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    Been discussed before but all seem older threads. Am wondering if insights on this have changed. What is the right level to maximize battery life for a daily charge? I got a P85D and drive about 40 miles to work round trip. Used to do 90% but is the wisdom still that 50-70% is healthier to maintain maximum charge over time? Thanks.
     
  2. David99

    David99 Active Member

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    The general rule is that the lower the state of charge, the longer the battery will last. If you only need 40 miles per day you can just charge to 50% and be totally fine in terms of range. But it's reasonable to charge a little higher to give you some buffer in case you need to drive more. In your case I'd probably go to 60 or 70%. I think you don't have to be too concerned about battery life as long as you stay mostly below 80%. Charging to 90 or 100% isn't bad if you start driving right away. The factor is time. If you charge it to 100% and let it sit like it for a long time, that would be bad.
     
  3. steilkurve

    steilkurve Member

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    Ok. Thanks. So the trick is to not top it off regularly and instead keeping it at the lowest charge level you can live with? It doesn't matter if the charge routinely goes under 50%, which may happen if I max charge at 70% all the time.
     
  4. tga

    tga Active Member

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    I don't have the reference handy, but someone once tweeted Elon something along the lines of: "If I only need 20% of the battery per day, is is better to charge to 60% (keeping the battery in 40%-60%) or 90% (keeping the battery in 70%-90%)." Elon replied with "40%-60%".

    In the long run, keeping the SOC averaged around 50% is best, but the impact on the battery keeping it in the 70%-90% range is pretty minimal.
     
  5. djp

    djp Roadster 2.0 VIN939

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    Here's the actual tweet:

    Low SOC, cool temperatures and shallow depth of discharge all help extend the life of Li-ion batteries.
     
  6. steilkurve

    steilkurve Member

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    Ok. Thanks.
     
  7. tga

    tga Active Member

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    Thanks for looking it up.
     
  8. Drucifer

    Drucifer Active Member

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    The Chevy Volt is "88% -> 23%", I take that as a hint that doing 70% -> 40% will work great - essentially charge such as the battery median charge is between 50% and 60%
     
  9. cottylowry

    cottylowry 2013 Model S

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    So then on a long trip, say cross country, can one always charge to 100% and hit the road as soon as possible, if you think you may need the max range?
     
  10. gavine

    gavine Petrol Head turned EV Enthusiast

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    Yes...
     

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