TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC
Start a Discussionhttps://teslamotorsclub.com/tmc/tags/

Screen shot of supercharging predicts range (non-linear math) of 282 miles

Discussion in 'Model 3' started by insaneoctane, Jun 22, 2017.

Tags:
  1. insaneoctane

    insaneoctane Member

    Joined:
    Apr 6, 2016
    Messages:
    778
    Location:
    Southern California
    This thread is to discuss the new photo of supercharging and the math to extrapolate the range. All the predictions I've seen so far assume a linear charge rate which is inaccurate.
    As seen in the graph here:
    [​IMG]
    The charge rate is not linear.
    Assumptions:
    • 50 minutes of charge remaining (indicated in photo)
    • SOC will only go to 90% (green line from photo)
    • Range remaining at the time of the photo = 95 miles
    So, using the data behind the shown charge rate, I went to the 90% SOC and went BACKWARDS 50 minutes, which resulted in a SOC of 33.7%. Therefore, the photo must have been taken with the vehicle at a SOC of 33.7% and at that time the range of the vehicle as 95 mi. So to extrapolate what a 100% SOC is = 95 miles / 0.337 = 282 miles

    No one knows the size of this battery.
    [​IMG]

    Here's the google spreadsheet of the charge data:
    Supercharge Time Calculator
     
    • Informative x 11
    • Disagree x 2
    • Like x 1
  2. TexasEV

    TexasEV Well-Known Member

    Joined:
    Jun 5, 2013
    Messages:
    5,324
    Location:
    Austin, TX
    Way too complicated. The charge rate is not linear, but the battery icon is. It shows about 30% full at 95 miles. That's a simple linear equation to find what 100% charge is. The question is rated or ideal miles.
     
    • Like x 9
    • Helpful x 2
    • Informative x 1
    • Love x 1
  3. ItsNotAboutTheMoney

    ItsNotAboutTheMoney Well-Known Member

    Joined:
    Jul 12, 2012
    Messages:
    5,804
    Location:
    Maine
    Dumb back-calculation:
    If base 3 is 3/4 of the capacity (6 of 8 modules), and a lighter vehicle we would then expect range of at least 211.5 miles. Given the reduced weight the number's pretty consistent with hitting 215 miles on the base model with (6/8) x capacity(MODEL375).
     
  4. insaneoctane

    insaneoctane Member

    Joined:
    Apr 6, 2016
    Messages:
    778
    Location:
    Southern California
    If we *assume* the 282 mi range is the 75kWh battery and that the base model will have 60 kWh, then 60/75 = 0.8 and 0.8 * 282 = 225.5 miles of range with no mass reduction benefit considered. While 225 miles is > 215, I personally would be disappointed to not beat the Chevy.
     
    • Like x 1
  5. McRat

    McRat Active Member

    Joined:
    Jan 20, 2016
    Messages:
    4,246
    Location:
    Norco, CA
    If both the 60/75 options use the same kWh of buffer, then that also comes into play as well as true battery cell capacity, as 60/75 could just be nominal numbers. But nobody is going to know what the max usable is yet.
     
  6. Bokonon

    Bokonon Title-customizing Member

    Joined:
    Jan 28, 2016
    Messages:
    265
    Location:
    Newton, MA
    #6 Bokonon, Jun 22, 2017
    Last edited: Jun 22, 2017
    Agreed. The other issue with using the SoC chart and the "minutes remaining" readout as a guide is that it assumes no constraints on power availability (e.g. due to kW provided from the supercharger, battery temperature, etc). We saw that the car in question was paired with another supercharging vehicle and was only drawing 70 kW. Consequently, the car's estimate of "50 minutes remaining" could have been made under less-than-ideal conditions, in which case the car's actual charging curve would not align with the chart.
     
    • Like x 1
  7. insaneoctane

    insaneoctane Member

    Joined:
    Apr 6, 2016
    Messages:
    778
    Location:
    Southern California
    Yes, the battery icon is linear, but I wanted another route that didn't include counting any pixels and/or considering perspective of the photo! The math I used agrees with you and the photo (the snapshot looks confirms the calculated 33.7%).
     
  8. tsla007

    tsla007 Member

    Joined:
    May 6, 2016
    Messages:
    366
    Location:
    CT
    actually 312 according the the experts, but hey, getting close to 300 or a little over is incredibly nice to those who have waited so long.
     
  9. gowthamn

    gowthamn Science

    Joined:
    Apr 14, 2016
    Messages:
    235
    Location:
    Seattle
    A Model 3 with > 300 mile range? Who will by Model S 75 then? Its costs more and has less range. Most won't be ready to pay more just for interior space.
     
  10. JeffK

    JeffK Well-Known Member

    Joined:
    Apr 27, 2016
    Messages:
    5,369
    Location:
    Indianapolis
    #10 JeffK, Jun 22, 2017
    Last edited: Jun 22, 2017
    Seeing as people cannot buy a Model 3 right now unless they have a reservation, if they don't want to wait a year then they must get a Model S. If next year they decide to switch to 21-70s in the Model S then they can safely lower the price a bit and maintain the same margins.

    In the future the major money maker will be the Model 3. Consider in 2018 they will generate more revenue than all previous years of their existence combined.
     
  11. jgillispie

    jgillispie Member

    Joined:
    Sep 12, 2016
    Messages:
    250
    Location:
    Illinois
    Certainly the meat and potatoes argument. Tesla will have to figure out what the added luxury features and other differences of the S/X are worth(eg. 17 inch touchscreen, driver screen, auto charge port).
     
  12. jelloslug

    jelloslug Active Member

    Joined:
    Jul 21, 2015
    Messages:
    2,510
    Location:
    Greenville, SC
    Chances are the 75 will be replaced with a smaller version of the 100 battery soon. Simple math would put it around the 85 size.
     
  13. SageBrush

    SageBrush 2018: Drain the Sewer

    Joined:
    May 7, 2015
    Messages:
    4,486
    Location:
    Colorado
    Take your Model 3 on the highway -- where it matters. The poor Bolt does not stand a chance, even before your consider the anemic charging rates of CCS (presuming the CCS exists, which is fairly wishful thinking for now.)
     
    • Like x 1
  14. SageBrush

    SageBrush 2018: Drain the Sewer

    Joined:
    May 7, 2015
    Messages:
    4,486
    Location:
    Colorado
    #14 SageBrush, Jun 22, 2017
    Last edited: Jun 22, 2017
    I know people are optimistic that the Model 3 peak charge rate will be greater than 70 kW but I doubt it, based on C rates. It may be entirely simply a co-incidence that the recent Supercharger installations can supply up to 145 kW but if I am correct then Tesla has engineered the devices to supply two Model 3 concurrently at the maximum each car can accept.

    Continuing with the 70 kW charge theme, I am optimistic that reasonable ( ~ 70 mph) long trip speeds can be traveled at 250 Wh/mile, implying that after the initial charge is depleted further miles will incur an ~ 13 second charging delay, or about 20-25 minutes every 100 miles. My wife and I already stop for at least 10 minutes at those intervals in an ICE, so the additional wait is trivial for the trips we take and modest even for truly long drives.
     
  15. McRat

    McRat Active Member

    Joined:
    Jan 20, 2016
    Messages:
    4,246
    Location:
    Norco, CA
    #15 McRat, Jun 22, 2017
    Last edited: Jun 22, 2017
    Actually, commuting is where it matters. Most EVs are in California, and the rumors of 75 mph average urban freeway speeds are just that.

    I had to go to JPL yesterday (~Pasadena), then Irvine (OC), then back to the Inland Empire, 144 miles loop of several LA/OC/Inland freeways starting at 9:00am after rush hour. My peak speeds were about 90 mph. Low speed was 0 mph perhaps 50 times. Total trip time, 5 hours, or just under 30 mph average freeway speed. This is about optimum during daylight hours on weekdays, and I was allowed HOV lane access, or it would have been much longer.

    Our delivery truck would have consumed about 12 gallons of fuel or more in that kind of driving.

    But if you are on vacation and have tons of time, an EV is almost as fast as a Ford Fiesta. Not sure about the bragging rights, but what the heck.
     
  16. Saghost

    Saghost Active Member

    Joined:
    Oct 9, 2013
    Messages:
    4,906
    Location:
    Delaware
    If Tesla is using the same approach as they have before (fewer modules and a lower system voltage for smaller packs,) that's the big battery.

    The 364V shown is fairly close to what the 85 in Bjorn's time lapse shows in the same range, and much higher than the 70:



    Also, only 70 kW at ~30%?

    There could be something else limiting power, but that's not a promising number, especially for the larger pack.

    As for the range numbers, I think the ~300 miles that both approaches have produced is a reasonable rated range for the big pack - but remember, current cars have ideal range as an option, too, and I don't think anything here would tell you which is set...
     
    • Informative x 2
  17. Jayc

    Jayc Member

    Joined:
    Mar 28, 2016
    Messages:
    574
    Location:
    UK
    By the same argument, why buy Mercedes S class when the CLA offers around twice the mpgs?
     
  18. Saghost

    Saghost Active Member

    Joined:
    Oct 9, 2013
    Messages:
    4,906
    Location:
    Delaware
    Does every version of the BMW 7 series?have more power and faster acceleration than every 3 series?

    I don't think Tesla will have trouble finding buyers for the S after the 3 release, though I do think Tesla will be adding new luxury features in the coming quarters to more clearly separate the two.
     
    • Like x 1
  19. flamingoezz

    flamingoezz Member

    Joined:
    Apr 13, 2016
    Messages:
    336
    Location:
    NJ
    Agree here. Model S will be the technology leader. They will probably get an interior refresh in the next year, full autonomy first and probably a HUD ;)

     
  20. dsvick

    dsvick Active Member

    Joined:
    Jun 10, 2016
    Messages:
    1,489
    Location:
    NE Ohio
    There are a lot more factors than simply range and size. And Tesla has already stated that the S and X will be the technology leaders so there will likely be more reasons to go for an S in the future.
     

Share This Page