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 or making a Paypal contribution here: paypal.me/SupportTMC

Rated range affected by driving history?

Discussion in 'Model S: Battery & Charging' started by cinergi, Feb 20, 2014.

  1. cinergi

    cinergi Active Member

    Joined:
    Sep 17, 2010
    Messages:
    2,170
    Location:
    MA
    Yes, I know the title of the thread will piss people off -- please bear with me. Read the entire post, take a breath, and read it again before replying. We've been claiming rated range doesn't including driving history (that Tesla is confusing Projected with Rated) -- yet we don't have the source code. Please read on and then provide the details I'm asking for. I think it's critical to understand that, e.g., just because someone's pack is replaced and their rated range goes to 272 on 100% charge does not mean that driving history is not included in the calculations. Perhaps the source code has something in it that resets the calculation when a new battery is installed. There are many possible explanations. So I think it's presumptuous on our part to maintain this claim. Read on for the thing that made me "question my faith."

    Until a few days ago, I was in the camp that believed rated range did not have an element of driving behavior included -- that it was essentially a fixed calculation of kWh available / 290 Wh/m; projected is what includes driving behavior.
    Recently, I was in Aaron.S's car (firmware 5.8.4) and rated matched projected at 289 or 290 Wh/m. Later that day, I noticed that my rated matched projected at 300-303 Wh/m (firmware 5.8.7; low SOC so high margin of error). It used to be ~310. So now I'm no longer sure. The Tesla engineering team has told me that rated range is a complex calculation -- far more than just CAC/whpm.

    Another interesting piece of detail -- his lifetime whpm is 337 and mine's 356. 289 * (356 / 337) = 305.3 -- that's suspiciously close to my 300-303 above (which could easily be 305 if I had measured at higher SOC; see SOC comments below).

    Of course, we have different cars -- I have "A" battery and he has "B" ... and our FW is slightly different but now I'm wondering. I'd like more data points from folks here:
    * What does your 30 mile average whpm read when your rated range matches projected? No estimates please!
    * battery revision (A/B/...)
    * firmware version
    * lifetime whpm
    * Mileage on your current battery

    The math will be more accurate at higher SOC (since comparing "10" vs. "11" miles is a 10% difference and "100" vs. "101" is a 1% difference) so try to provide numbers at higher rated ranges.

    Note also that this whpm difference may or may not be related to the rated range number. But the fact that these numbers can be different absolutely calls into question whether the rated range number includes driving history or other similar factors.
     
  2. qwk

    qwk Model S P2681

    Joined:
    Dec 19, 2008
    Messages:
    2,817
    Up until October 13 my whpm was 309. From October to now, its 423 whpm. Max rated charge numbers are within 2 miles depending on the ambient temps.

    If the rated range calculations take driving history into account, it must not make that much of a difference.
     
  3. Zextraterrestrial

    Joined:
    Mar 11, 2010
    Messages:
    3,636
    Location:
    Humboldt/Los Altos
    explain ?

    356. 289 * (356 / 337) = 305.3

    ??

    =376
     
  4. bluetinc

    bluetinc Member

    Joined:
    May 11, 2009
    Messages:
    682
    Location:
    MD
    Hey Ben,

    Not to add more confusion into the mix, but I had been tracking this fairly closely before 5.X and felt I really had this well figured out. After 5.X I seem to have different numbers at different times and things stopped making sense to me. It almost appeared to me that the software was attempting to use different numbers depending on the situation (perhaps SOC), but I haven't had a chance to track this down. All I can say for sure is that my numbers are different from one time to the next when I have tried to take these numbers. I'll try to track this again and see what it's doing. I'll also see if I can track down the response from Tesla engineering where I felt they stated that rated range was not based on driving habits.

    Peter
     
  5. Zextraterrestrial

    Joined:
    Mar 11, 2010
    Messages:
    3,636
    Location:
    Humboldt/Los Altos
    just did a drive to get a matching # but only got to a 15mi match. 30 should be really close. 5 mi was close but at 15mi it was a lot more 'accurate' will add a 30mi if I get there (ever)

    ave - 280-282 Whr/mi for 15mi @ 123mi rated SOC ~55%
    - 276 Whr/mi for 5 mi @ 128mi rated **I expect the 30mi match to be right around 280

    battery - A
    Firmware - 1.49.83 (5.8 #2?)
    lifetime - 373.04 Whr/mi
    mileage - 20,150mi


    my data, that includes every single trip I've done except the first few, shows a match @ 280 Whr/mi if I exclude trips under 15mi and 272 if all trips are included
     
  6. cinergi

    cinergi Active Member

    Joined:
    Sep 17, 2010
    Messages:
    2,170
    Location:
    MA
    The "." after 356 is end-of-sentence not a decimal point :)

    - - - Updated - - -

    These numbers compared with mine suggest that lifetime whpm isn't a good indicator. It may be something like the last 1,000 miles but who knows -- we'd have to reset our trip meters and report in at 1,000 to see if it's any better. Bummer.

    What we *can* see however is that we've now got 3 completely different numbers for when rated matches projected. Clearly there's a variable in the whpm calculation -- and if that's true, it's likely (though to be fair, not necessarily) true that rated range has a variable in it, too.

    Are you able to tell where your "rated range" horizontal guide line is on the energy graph? Is it around 300 or closer to 280?
     
  7. Zextraterrestrial

    Joined:
    Mar 11, 2010
    Messages:
    3,636
    Location:
    Humboldt/Los Altos
    haha , decimal.

    I think the rated line is closer to 280.

    you want my last 1000 miles Whr/mi? easy.
    1000 mi 390.2 kWhr
    390Whr/mi


    I don't think there is a variable in rated range. The battery reserve might have changed and balancing of different batteries might be different but haven't seen any variation in rated or ideal
    there is a tiny curve if you put a bunch of telemetry data for Rated vs ideal but pretty close to a straight line
     
  8. jerry33

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

    Joined:
    Mar 8, 2012
    Messages:
    12,763
    Location:
    Texas
    * What does your 30 mile average whpm read when your rated range matches projected?
    I've never seen that.

    * battery revision (A/B/...)
    B

    * firmware version
    5.8.7 (1.49.84)

    * lifetime whpm
    257

    * Mileage on your current battery
    18,497

    The bar on the Energy screen is at 300 as near as I can tell. It's not as if you can see the graph markings as they are covered up by the "information". I hardly ever use the energy screen as it doesn't seem very useful because 30 miles is just too short.
     
  9. slipdrive

    slipdrive Member

    Joined:
    Aug 30, 2013
    Messages:
    196
    Location:
    Colorado
    I really appreciate all the detail folks put into these questions.

    I have a couple simple ones. 1) how and I find lifetime whr/mi ? and 2) Is there is way to display kwH instead of rated miles ?

    I would just like to know what the SOC% is with some accuracy, and be sure my "tank" hasn't shrunk.

    Thank you.
     
  10. qwk

    qwk Model S P2681

    Joined:
    Dec 19, 2008
    Messages:
    2,817
    The way to tell would be to get as near as possible to the rated range bar, and add/subtract power until the average line matches the rated line(line will be solid and not dashed). Mine is exactly 302 rated. Loaner 9230 was 306.
     
  11. jerry33

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

    Joined:
    Mar 8, 2012
    Messages:
    12,763
    Location:
    Texas
    1) how and I find lifetime whr/mi ?

    I have it because I've never reset the trip metres.

    2) Is there is way to display kwH instead of rated miles ?

    Sorry, don't know.

    3) I would just like to know what the SOC% is with some accuracy.

    SOC is not an exact science. The only way to know for sure how much you have left is to balance the pack (how you tell if the pack is balanced is a whole 'nother subject), charge to 100% and then run to 0%. Of course, doing that is hard on the battery. Tesla uses some estimations that change with the firmware revisions as they figure out better (hopefully) ways to do the estimation.
     
  12. qwk

    qwk Model S P2681

    Joined:
    Dec 19, 2008
    Messages:
    2,817
    BTW, these numbers have not changed with different firmware versions. I'm currently on 5.8(.24).
     
  13. Jeff Miller

    Jeff Miller Member

    Joined:
    Jan 2, 2013
    Messages:
    293
    Location:
    Chicago
    * What does your 30 mile average whpm read when your rated range matches projected?
    I haven't paid attention to projected range so am not sure.

    * battery revision (A/B/...)
    B, 85kwh battery

    * firmware version
    5.8.7 (1.49.84)

    * lifetime whpm
    334

    * Mileage on your current battery
    5073

    Right now my 30 mile average is 359 whpm and my projected range (at 60% charge) is 110m.
    and my rated range is 134m.

    I definitely notice rated range fluctuating. In warmer weather I see 138 and in very cold weather it's
    more like 125 at 60% charge. I assumed the algorithm adjusted the rated range according to current temperature,
    but maybe you are right and it depends on recent driving history in some way.
     
  14. brianman

    brianman Burrito Founder

    Joined:
    Nov 10, 2011
    Messages:
    15,487
    I think "driving history" is a (poorly worded) alias for "climate". ;)
     
  15. stevezzzz

    stevezzzz R;SigS;P85D;SigX

    Joined:
    Nov 13, 2009
    Messages:
    6,062
    Location:
    Colorado
    Battery pack: A 85kWh
    Firmware: 5.8.7
    Battery pack mileage: 19,950
    lifetime Wh/mi: 315
    30 mile average Wh/mi when Projected miles equals Rated: 301 (SOC ~85%)

    I saw Rated equal to Projected miles four times tonight at SOC's ranging from 85% down to about 50%: Wh/mi at those times were 300, 297, 299 and 298.
     
  16. Mnlevin

    Mnlevin Member

    Joined:
    Feb 4, 2013
    Messages:
    417
    Location:
    South Florida
    Wow this thread is way over my head and seems like a science class. But throwing in my simple information is that we have a 60 and have seen the max charge RR shrink from 205 when new to 195 currently with 18670 miles and avg wh/mi lifetime showing 315. Something else of note was on my current long distance trip while highway driving constant @ 70mph my wh/mi was at 301 but when driving back roads avg around 55 mph for 80 mi it was around 330. This was driving from th Pt Orange SC to Ocala so it wasn't a short trip. Without the tech knowledge I believe that the Rated Range does factor in lifetime avg wh/mi but in any event it doesn't matter to me as much as long as my battery degradation doesn't happen much. Hope it still shows over 190 RM @ 100% after 60k miles. We usually charge to 80% daily and have done about 20 max charges when expecting a long driving day
     
  17. rlang59

    rlang59 Member

    Joined:
    Feb 27, 2013
    Messages:
    923
    Location:
    US
    Here is a piece of data from my car (60) 11416.3mi lifetime Wh/mi of 317. Today I did a "trip" charge (didn't complete was in the calculating time phase) and my ideal range of 229, as it should but rated only shows a range or 199. Also for me to get my energy meter and rated display to line up i need to be in the 286 wh/mile area. My records show that when my car updated to 5.6 I "lost" ~8miles of rated range, note that this wasn't when they changed the standard charge to 90% from 93% (that was 4.5).

    My take on this whole thing is that in my case at least one of the updates screwed up the rated range number but I haven't lost any range. I typically can go around 5 miles without seeing the rated range number move and that is with an average of around 310-320Wh/mi.
     
  18. jamieb

    jamieb Member

    Joined:
    Oct 26, 2013
    Messages:
    153
    Location:
    Sacramento
    #18 jamieb, Feb 21, 2014
    Last edited: Feb 21, 2014
    Software request to Tesla - put the lifetime WHr/mile stat on the Model S Splash Screen and allow owners to use the two trip meters for other purposes.

    Either that, or allow the My Tesla homepage to poll the car daily and provide up-to-date stats including lifetime energy use and mileage. Further functionality could be similar to the "about this Mac" menu item and the 'system report' in Mac OS X that provides detailed listing of all the sub-systems on the computer - an "about this Tesla" could display a similar breakdown of details about our cars (battery versions, software updates, installed hardware, etc.). The data is all there - we're all driving computers, after all.
     
  19. gaswalla

    gaswalla P4201/85/airsusp/pano/19i

    Joined:
    Sep 23, 2012
    Messages:
    1,202
    Location:
    San Diego
    The rated range calculation is clearly much more than a raw calculation based on whr/mi. There was a recent thread here, and I can confirm that putting the car into "range mode" from settings increases the rated range regardless of SOC. People should be adding whether the care is in range mode or not in the above reports.
     
  20. paulkva

    paulkva Member

    Joined:
    Jul 22, 2013
    Messages:
    567
    Location:
    Falls Church, VA
    Battery pack: 85 kWh, probably rev B (I haven't had a chance to look, but my VIN is ~18000)
    Firmware: 5.8.4 (1.49.57, and I haven't been offered anything newer yet)
    Battery pack mileage: 4,950
    Lifetime Wh/mi: 324
    30 mile average Wh/mi when Projected miles equals Rated:
    * 292 Wh/mi @ 134 mi Projected/Rated
    * 293-294 Wh/mi (I saw both) @ 117 mi Projected/Rated
    And for what it's worth, I always keep the HVAC in range mode.
     

Share This Page