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Charging Reduction rather Quickly??

Discussion in 'Model S: Battery & Charging' started by themacs, Jan 2, 2015.

  1. themacs

    themacs Member

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    san clemente, CA
    Just an easy question (probably) for most.

    I bought the car 2 months ago. "Normal" charge was 261 miles. That being the setting suggested by Tesla for a normal (80% I think) charge.

    I realize you lose some "miles" as the car gets more miles, but in 1,500 miles (I bought the car from Telsa with 7,300 and now have 8,800) my 80% charge is now 232 miles.

    Does this sound normal? A 11% reduction that quickly :confused:?

    Thanks for any thoughts and Happy New Year!
     
  2. CRASCH

    CRASCH Member

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    No it does not sound normal as you described it. But I think it can be explained away. There are two ways of measuring range rated 100% (265) and ideal (300) .

    The first thing to check would be if you are in ideal or rated. Perhaps it was switched (IIRC Settings, Measurements & units), it will also say under the range screen dash and charging.

    An 80% charge of ideal miles would be +/- 240 and rated +/- 212.

    My guess is that it was originally charged to 90% (270) in ideal mode and you are showing Ideal range at 80% which should be 240 with a healthy and balanced battery. You should be able to get back a most of the miles by balancing your battery. There are several threads about it. Basically you run your battery down to about 10% and then charge it back up to 100% a couple of times. I suggest you find and read those threads as there is more to it than that...
     
  3. Bighorn

    Bighorn Member

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    Something with your numbers is amiss. Are you in rated or ideal miles? 261 is closer to a 100% charge with rated miles. 232 is about right for 90% charge.
     
  4. Todd Burch

    Todd Burch Electron Pilot

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    On top of what others have said, if you always charge to 80% instead of 90%, the car seems to start to more quickly misjudge how much energy's in the pack over time. You are not seeing real battery degredation...just a manifestation of the algorithm for determining range. Determining range remaining is a *very* challenging problem, and Tesla's been tweaking and evolving the algorithm ever since the Model S has come out...it will continue to be a challenging problem for some time. The best way to recalibrate is several discharges down to low states of charge, then charging back up--but this sort of usage pattern promotes *real* degredation. Many have found that charging to 90% for awhile will slowly start creeping the numbers back up. Either way, it's just a miscalibration thing and not real degredation.
     
  5. themacs

    themacs Member

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    How do I know if I am in Ideal or rated? Which should I be in?

    I will run down to 20-30 miles and charge to 90% if that is what is needed.

    Anything else I should do?

    Thanks to all!
     
  6. GetAmped

    GetAmped Member

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    @ themacs

    You can change whether the car measures distance in "Ideal Miles" or "Rated Miles" under "Settings/Measurements and Units". Ideal is pretty much useless IMHO, I have mine set to Rated.
     
  7. Todd Burch

    Todd Burch Electron Pilot

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    I wouldn't do this just to try to recalibrate...you'll be doing more harm than good.
     
  8. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Right. The numbers shown are really just estimates. The best information on real degradation is that the first year you lose 5% and then 1% every year thereafter. Based on Roadster statistics, ambient temperature doesn't have a big effect due to the liquid cooling. Running from 100% to 0% frequently will increase degradation, as will leaving the car at a very high or very low charge level for a long time.

    Best advice is to just drive it, do a range charge if you need the extra range, keep in mind what's known to be bad for the batteries, and don't worry too much about what the numbers say.
     

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