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Plug In America Tesla Roadster Survey

Discussion in 'Roadster' started by tomsax, Jan 15, 2013.

  1. tomsax

    tomsax Member

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    #1 tomsax, Jan 15, 2013
    Last edited: Jul 14, 2013
    In late 2010, I did a small, informal survey of Roadster owners in the Northwest to get some idea of how our battery packs were holding up. The top-level result was that we were seeing very little degradation, with small variations between packs being a larger effect than capacity loss from use. When the controversy with LEAF battery pack degradation in hot-weather climates emerged last year, I did broad survey of LEAF owners and shed enough light on the subject that Nissan's Andy Palmer recently encouraged every LEAF owner to read the survey results paper.

    Now, I'd like to return to the Roadster and do a more thorough study across the full Roadster owner base. My goal is to find answers to questions like these:

    • How does the Roadster battery pack hold up over time and miles?
    • How does our battery pack degradation compare to Tesla's original guidance that the our packs will have 70% to 80% of original capacity after 7 years or 100,000 miles?
    • How well does the Roadster's active thermal management protect the battery pack against hot and cold weather?
    • How do version 1.5, 2.0 and 2.5 Roadsters compare in battery longevity and major maintenance?
    • What about Roadster vs Roadster Sport?
    • How many Roadster owners have had major drivetrain component replacements?
    • Now that the factory warranties are ending on more and more Roadsters, what would the value proposition be for an extended warranty?
    I hope this will be a valuable community resource in both the near future and long term.

    Contribute to the Study

    I invite all Roadster owners to participate in this study. I takes just a few minutes to fill out the survey form, available here:


    The survey asks for your name, email and VIN sequence number, but keeps those fields private. Your private contact info will not be used for any purpose other than the survey. Except for those private fields, all of the survey data will be available for others to examine and analyze.

    After you've filled out the form once, there's an update form you can use to correct or add a value, or to do an update with newer info, without filling in the values that haven't changed. Submit as often as you like, records are grouped by vehicle so there's no problem with having multiple reports on the same vehicle.

    Results Released at Teslive, July 13th, 2013

    I released results from the Roadster Battery study, using data collected from the survey and via OVMS.

    A quick summary of the major results:

    The projections from the various data sets studied suggest that Roadster batteries will be
    at 80% to 85% capacity after 100,000 miles, on average. Stated another way, the study
    shows an average loss of about 3.7 ideal miles of range (1.6%) per 10,000 miles driven.
    As there is considerable variation among vehicles with similar mileage, an individual
    owner’s experience may vary significantly from the average.

    The survey found no significant correlation between climate and battery pack longevity.
    Individual experience may vary. The survey data for high-mileage vehicles is sparse with
    little variation in climate among those vehicles, so it’s possible an effect from climate
    will emerge as more data is collected.

    The survey found no significant correlation between vehicle age and battery pack
    longevity, although the study has no data on the first year of use, nor use beyond 4.5
    years.

    The full paper with more detail is here:

    Plug In America Roadster Battery Study Results Paper

    For an overview of the data showing survey participants by geographical area visit this page: Survey Results page.

    The Vehicles List page shows an abbreviated table of the survey data, sortable by various criteria, which provides an easy way to examine some of the most interesting information collected.

    The full survey data is available for download in tab-delimited test and JSON formats, see the Results page for the links.
     
  2. Jackyche

    Jackyche Member

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    I tried to fill it out but it said my odometer value is not a valid number.
     
  3. hcsharp

    hcsharp Active Member

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  4. strider

    strider Active Member

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    Same question as hcsharp. Isn't Rich working on some of this data? Any way you could piggy-back on what he's doing. Though that reminds me, I need to go pull my logs again for Rich :redface:
     
  5. markwj

    markwj Moderator, Asia Pacific

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    Many thanks to Tom for doing this. The roadsters have a lot of good data for the EV community, and it will be interesting to see the results.
     
  6. tomsax

    tomsax Member

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    Yes, definitely. I worked with Rich to add features to my log parser to get him the data he wants. I do encourage everyone to participate in his effort as well.

    The Plug In America survey is simpler in the data it collects and doesn't require capturing and emailing giant log files or running wacky command-line programs. Rich's survey can potentially look at a much more detailed data set, but can't get some things like ideal miles. I want to figure out how battery packs, etc., are performing across as many owners as possible, with some basic info to shed light on any patterns (like climate and general driving habits). Rich wants to look at similar issues, but from data in the log files.

    Please do participate in both. Rich and I will work together. He lives just a few miles from me, and we've been friends since long before the Roadster was a gleam in Martin Eberhard's eye.
     
  7. strider

    strider Active Member

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    Added my data. Now off to run the parser on my logs for Rich...
     
  8. brianman

    brianman Burrito Founder

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    Have you guys heard anything (that you can share) yet regarding logs for Model S?
     
  9. Timothy

    Timothy Driving on Sunshine

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    I posted this in the above thread as well. I wonder if what Tesla told me is a different approach to the same question--battery state and battery life?

    Being a non-techy biology type, you guys are speaking a different language than I do. Anyhow, I just had my annual service at Tesla Menlo and asked them about the battery as I had noted the ideal standard charge had dropped from 184 to 176 since I bought the car.

    I was told the best way to evaluate the battery is with the CAC (Calculated Amperage Capacity?) New cars are supposed to have 16 (who knows what units?) My car was manufactured 12/2010 and I bought it new 5/2011. At the car's service 12/2011 the CAC was 153. At the recent service 12/12 it was 147. I was told the 8% drop in 2 years since manufacture was 'normal.'

    I drove from Menlo after the service to Santa Barbara (300 miles) and had about 25 ideal miles left on standard mode when I arrived. I charged in range mode--217 ideal miles--and unplugged the car and let it sit for a week to balance the battery. No change in the standard charge since. 175 ideal miles tonight after the standard charge completed.

    So can any of you explain if this is a good way to evaluate the battery--and what it all means?

    =========================
    I answered the Plug in questionaire--only 30 some odd of us have. C'mon! Take the time to do it!!!:smile:
     
  10. tomsax

    tomsax Member

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    Study Update

    So far, 49 owners have contributed to the survey, very good progress for less than a week! Thanks to everyone who has contributed.

    Word has been spreading through a number of local owner mailing lists. Please keep telling your fellow Roadster owners about it. I'm hoping to get to 100 participants by the end of the month. I want all sorts of owners: low mileage, high mileage, low VINs, late VINs, hot climate, cold climate, moderate climate, heavy use daily drivers, weekend cars, garage queens, everything.

    Since the survey was launched, I've added a few questions in response to suggestions from the community:

    • Has your motor been swapped?
    • What was your odometer on delivery?
    • What is your CAC value?
    If you've already submitted, you can add or amend values to your report from the Update Form. Just enter your name, email and VIN sequence number and it will take you to the survey form with all of your previous values already filled in. Choose "correct an error or omission" if you just want to amend your previous report and choose "submit a new report" if you want to give more current information. (The latter option fills in the fields that are least likely to change over time leaving values like odometer and standard/range capacity blank.)

    It's been great chatting with some oldtimers as well as meeting new owners. Thanks to everyone who has helped improve the survey by making suggestions or reporting issues.
     
  11. Timothy

    Timothy Driving on Sunshine

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    Check your data--those of you who have submitted information. One car is listed as being a 2010 model--built in 2013!
     
  12. wiztecy

    wiztecy Active Member

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    #12 wiztecy, Jan 21, 2013
    Last edited: Jan 21, 2013
    We should probably also remind people to give the standard and range mode charge after allowing 20 mins for the battery to settle and balance. At least have some standard of "n" minutes of sitting. I think some of the numbers may get skewed if the pack hadn't balanced correctly. I can get 249 Range mode miles right at charge cut-off but after letting the pack sit for 20 mins settles in at 232 and then the pack's bleeding it off from there.
     
  13. strider

    strider Active Member

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    There is a statement about "measuring battery capacity" that says you should wait before reporting the reading.
     
  14. djp

    djp Roadster 2.0 VIN939

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    Wow.. 8 battery swaps and 9 PEM swaps out of 53 Roadsters?! That's almost a one-third failure rate between the two biggest ticket items. I'll have to rethink the extended warranty
     
  15. tomsax

    tomsax Member

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    The survey is up to 71 vehicles with 10 battery swaps and 12 PEM swaps, and actually that's the count of vehicles that have had battery or PEM swaps, some of which have had multiple. I want to get to 100 vehicles with at least 30 CAC values to have a good sample set.

    Please submit your vehicle if you haven't already, or update your previous report if your numbers have changed significantly or you can add your CAC value.
     
  16. markwj

    markwj Moderator, Asia Pacific

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    #16 markwj, Feb 16, 2013
    Last edited: Feb 16, 2013
    Just a comment on battery swaps; there is a big fuse in there. My battery swaps have been to change the fuse (caused by something else blowing) - the battery sheets themselves have been fine.

    That said, it is a horrendously labour-intensive job to replace the battery.

    Edit: I should also point out that my problems have been in the first six months. The past eighteen have been fault-free.
     
  17. ChadS

    ChadS Petroleum is for sissies

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    I have a similar note (to markwj's) on the PEM swaps. My car counts as one of the PEM swaps, but the car was working just fine. It had a small ground leak during J1772 initialization. Most chargers didn't even notice and it worked just fine. Coulomb chargers noticed though, and wouldn't let the car charge.

    While this was a problem with the PEM, it was a small one and one that would be very difficult for Tesla to have found at the factory because J1772 wasn't finalized and Coulomb chargers weren't built until after the car was shipped. So I'm not sure if you should count that or not. I guess if it was out of warranty and you wanted it fixed, you would have to pay for a new PEM (too bad they won't replace smaller parts inside!), so it probably should count. But I don't think it's a significant indicator of poor build quality or failing parts.
     
  18. hcsharp

    hcsharp Active Member

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    Bottom line is you had to replace the PEM in order to use Coulomb public chargers. So it counts. You can debate whether this is an indicator of build quality or not. I don't think that matters to most people. We're trying to get data to help determine whether to buy the extended warranty, not build quality. At least that's what i hope to get out of it.

    I agree it's too bad they won't repair them. There's a lot of parts in there and in most cases you probably only need to replace one.
     
  19. tomsax

    tomsax Member

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    The survey is up to 95 vehicles. I'd like to hit 100 before I start doing the data analysis, so I just need a few more owners to contribute.

    Roadster Survey Form

    I'm also interested in getting more CAC values. If you've already reported, you can use the update form to do an update and add your CAC value.

    Roadster Survey Update Form

    Thanks to everyone who has contributed. I think the results from this study will be very interesting.
     
  20. Doug_G

    Doug_G Lead Moderator

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    Some people probably don't know how to get CAC, so perhaps you should post the instructions again.
     

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