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Rated range goes down quickly

Discussion in 'Model S: Battery & Charging' started by totem, Sep 7, 2015.

  1. totem

    totem Member

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    Hi all,

    I am new to owning a Model S 85 and have noticed that the rated range goes down very quickly. As an example, today my family (of 5, 3 of them are kids of 8 and 3 years old) went to grab something quick. Here's the info:
    • Model S 85 with standard 19" rims in covered garage
    • Fully charged (for daily use) @240 rated miles
    • Outside temp: ~98 degrees F (yes, in Texas)
    • Pre-cooled car 3 mins before
    • A/C temp set: 71 degrees F
    • Drove 2 miles total: 1 mile there (family waited in car for ~7 mins, again at 71 degrees F) then drove back 1 mile
    • Pretty flat terrain, no hills at all
    • Avg MPH: 45
    • No fast acceleration

    Result: got back and the car said I had 233 rated miles left. Is this expected?

    I am planning on a trip that will be ~170 miles (no stopping to re-charge) soon mainly going ~60 MPH, and I worry that the range that is telling me is just not right or that the battery is not keeping charge well. Do I need to have the service center check on my battery?

    Thanks
     
  2. LetsGoFast

    LetsGoFast Active Member

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    Someone smarter than me probably has a more detailed answer, but I have noticed that I often lose miles at 4 or 5 to one for the first couple of miles, especially if I pre-cool. It goes to normal consumption after the first few miles. You might want to watch it on a longer trip and see if you see the same thing.
     
  3. Soolim

    Soolim Member

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    The drop from 240 miles to 233 miles need not be cause for alarm for a 2 mile drive assuming you left the A/C on for 7 minutes while family waited in the car, and you pre-cooled it for 3 minutes. Beside cooling the interior of the car, energy is also used to cool the car. However, I do not recommend charging to 100% if 80% is adequate for your daily drive. 80% to 50% charge prolongs the life of the battery. This is due to the battery chemistry.

    If it makes you feel better, by all means contact your service center for additional information. Is the S85 brand new? Enjoy your S85.
     
  4. eye.surgeon

    eye.surgeon Member

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    Congrats on the new car. Rated miles fluctuation over a 2 mile drive mean nothing. Drive it and enjoy. If you're like most of us here, within a month you won't even be looking at your rated range because it's not a factor for 95% of your driving. In fact I suggest you change your display to percentage charge. It's more informative.
     
  5. dsm363

    dsm363 Roadster + Sig Model S

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    Wouldn't worry about it. Charge to 100% for your long trip and complete charge right before you take off. Then drive speed limit for first part of trip and see what happens to your range. Program destination into the Nav too and it will give you estimate of how much range you'll arrive with.
     
  6. Nigel16494

    Nigel16494 Member

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    I agree, I cannot live with the miles rated range. I have to use percentage and that makes life very easy. Home to office is 9%, better than using 34 miles rated for a 19 mile drive. If you want to know what happened then look at the Wh of the drive. I think mine hovers around 330 with a lifetime 336. Isn't rated range based on 240 ?
     
  7. iadbound

    iadbound Member

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    I find rated range drops quickly out of the gate maybe 5 miles of range after driving 2 miles, but then it smooths out (does not include leaving the car on). However, the other day, I was on a longer drive where the first few miles included a stop and my rated range dropped a bit, but after that I was running so well that I actually beat the rated range by a couple of miles.

    - - - Updated - - -

    I think it's around 270-280 (at least from my experience).
     
  8. dsm363

    dsm363 Roadster + Sig Model S

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    I thought rated range was about 310 Wh/mile. Not sure about that.
     
  9. TexasEV

    TexasEV Active Member

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    What you described is typical for a short drive. Don't even bother looking at it when you're just driving around town. There is great fluctuation in Wh/mi in the first few minutes of driving.
     
  10. Khatsalano

    Khatsalano Member

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  11. totem

    totem Member

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    Thanks for the info everyone.


    The pre-cooling happened at the house while it was plugged in, so there shouldn't have been any loss of energy during that time of pre-cooling.
    I only have done the recommended charge of 240 miles for daily use (and will continue to do so), or is that too high for daily use to continue to have the best chance of keeping the life of the battery?
    I'll switch to percentage. Also, I will keep track of the true mileage & energy consumption.


    @Soolim, thanks, really liking it so far. It is a 2014 Model S 85.


    Very good links regarding the models Khatsalano, thanks.
     
  12. dsm363

    dsm363 Roadster + Sig Model S

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    I just charge to 90% and don't worry about it. Some say to 80%.
     
  13. mknox

    mknox Well-Known Member

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    Rated (or Ideal) Range numbers, as far as I can tell, are just a linear extrapolation of how much energy you have in your battery pack. If you charge up to 100% and you see 265 Miles, it will count down not based on how many miles you drive, but how quickly the battery discharges. For this reason, I've change my dash to show % because a linear 0-100 makes more sense to me than a linear 0-265. I use the range estimator on the Energy screen to see how many miles the car thinks I can actually go based on current conditions.
     
  14. totem

    totem Member

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    Ok, data from today:
    • Car garaged (not hot at all - very little to 'cool down')
    • Charged to 90% (240 rated miles)
    • Temperature of AC throughout the day: 71 F (again, in Texas, and it is hot: got to ~100 F today)
    • Miles driven: ~54, broken in many legs:
      • 6.7 miles x 2
      • 12.1 miles
      • 6 miles
      • 6.3 miles x 2
      • 9.7 miles
    • At the end:
      • 63% battery remaining (or 170 rated miles)

    Is the ~16 miles difference something telling me that there's something to be checked out with the battery or is something like this expected in your experiences?

    Thanks
     
  15. Enadler

    Enadler Member

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    I wouldn't worry about it. In over 2 1/2 years of driving, I have found that, just like an ICE, short trips tend to use more range than a single long trip. City driving also uses more energy than highway driving. Your original post talks about a 170-mile trip. Don't even sweat that. Just charge and go!

     
  16. mknox

    mknox Well-Known Member

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    When you set your energy display to Rated Miles, all it's doing is calibrating the gauge from 0-265 miles similar to when you set the display to % it calibrates it from 0-100. If you consume energy faster, you will go from 100% down to 0% or from 265 Miles to 0 Miles quicker. That is all. There is no real "intelligence" here. For a more accurate prediction of how much range you have left, use the Energy App.
     
  17. Max*

    Max* Autopilot != Autonomous

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    Yes. Many short trips, and those are short trips, will make it seem like your battery has a hole in it. Don't stress it. Turn on range mode, hit the highway, and drive (nonstop) for 150 miles going the speedlimit. See your rated range drop much less slowly.
     
  18. Soolim

    Soolim Member

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    My calc and analysis shows:
    90% - 63% = 27%. (% energy consumption for the 54 aggregated miles)
    27% of 85kWh = 22.95kWh or 22950 Wh energy consumed
    22950Wh / 54miles = 425Wh/mile energy consumption per mile traveled.
    The EPA Wh/mile for S85 is 311Wh/mile.

    I suggest that you reset one of your trip meter and start accumulating an one week performance of your car to monitor your average Wh/mile. Depending on the terrain, weather(hot and cold), tire pressure, city versus highway driving, and driving style all affects the Wh/mile. I have not traveled to places as hot as 100F with my car, so I cannot provide any opinion on the energy consumption of the A/C to cool 100F to 71F.

    Use of regen also helps a little in improving Wh/mile plus minimizes wear on the brake pad.

    Since you bought an 2014 S85, the car might be estimating the rated miles using the previous owner life time Wh/mile performance. As many have said, try getting the readings in % of energy consumed so that it is decoupled from the Wh/mile factor. Then you will have a better gauge of the battery and drive train performance. You can compare the trip recorder Wh/mile after one week driving to the EPA rated Wh/mile.
     

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