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Roadster 3.0

Discussion in 'Roadster' started by DrComputer, Dec 26, 2014.

  1. DrComputer

    DrComputer Member

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    Here's an e-mail from Tesla that I just received:

    Roadster 3.0
    Battery technology has continued a steady improvement in recent years, as has our experience in optimizing total vehicle efficiency. We have long been excited to apply our learning back to our first vehicle, and are thrilled to do just that with the prototype Roadster 3.0 package. It consists of three main improvement areas.

    Batteries
    The original Roadster battery was the very first lithium ion battery put into production in any vehicle. It was state of the art in 2008, but cell technology has improved substantially since then. We have identified a new cell that has 31% more energy than the original Roadster cell. Using this new cell we have created a battery pack that delivers roughly 70kWh in the same package as the original battery.

    Aerodynamics
    The original Roadster had a drag coefficient (Cd) of 0.36. Using modern computational methods we expect to make a 15% improvement, dropping the total Cd down to 0.31 with a retrofit aero kit.

    Rolling Resistance
    The original Roadster tires have a rolling resistance coefficient (Crr) of 11.0 kg/ton. New tires that we will use on the Roadster 3.0 have a Crr of roughly 8.9 kg/ton, about a 20% improvement. We are also making improvements in the wheel bearings and residual brake drag that further reduce overall rolling resistance of the car.

    Summary
    Combining all of these improvements we can achieve a predicted 40-50% improvement on range between the original Roadster and Roadster 3.0. There is a set of speeds and driving conditions where we can confidently drive the Roadster 3.0 over 400 miles. We will be demonstrating this in the real world during a non-stop drive from San Francisco to Los Angeles in the early weeks of 2015.

    We are confident that this will not be the last update the Roadster will receive in the many years to come.

    Happy Holidays.
     
  2. Doug_G

    Doug_G Lead Moderator

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    Okay, so 31% more energy means 3.2 Ah cells.
     
  3. bonnie

    bonnie Oil is for sissies.

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    I'd be happy to volunteer my Roadster for these tests, if Tesla has a hard time finding one to use :). Just sayin'.
     
  4. Doug_G

    Doug_G Lead Moderator

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    Now that we know this thread is really about "Roadster 3.0", I have renamed the thread. Again! :biggrin:

    Oh and I made the thread sticky.
     
  5. djp

    djp Roadster 2.0 VIN939

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    Woah - that's awesome, but not what we expected at all! They're not using a Model S cell, but one with a lot LESS capacity. I wonder if the S cells would have been too heavy?
     
  6. dpeilow

    dpeilow Moderator

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    Disappointing. 50% improvement is 366 miles under the old EPA test. Getting to 400 miles is going to require serious granny driving.

    - - - Updated - - -
    That's the link to the cells I just posted...

    - - - Updated - - -

    No it's the same as the latest Model S. The older Model S pack was 3.1 Ah.

    - - - Updated - - -

    They forgot the all important £ $ €.
     
  7. Botbldr45

    Botbldr45 Member

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    Disappointing? ........ Are you kidding!
    I'll take 366 miles with a big a## Tesla grin any day!
    ........ and granny driving?
    Just remember the Little Old Lady from Pasadena!
     
  8. scaesare

    scaesare Active Member

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    Hmm. Aren't the roadster cells 2.2Ah?

    31% additional capacity is 2.9Ah...
     
  9. dpeilow

    dpeilow Moderator

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    I'll take 366 miles at the right price too, but don't expect to get 400 without serious hypermiling.

    - - - Updated - - -

    No production Roadster is 2.4 Ah.
     
  10. djp

    djp Roadster 2.0 VIN939

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    The Model S cells should give a 82kWh pack, not 70kWh.

    6831 / 7104 * 85kWh = 82kWh
     
  11. Eberhard

    Eberhard #421 Model S #S32

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    or Tesla is just using those cells which fail to pass the quality-test to match the minimum capacity for a model S pack. Tesla just downrated the cells and are still fine for the roadster 3.0 upgrade batterypack
     
  12. dpeilow

    dpeilow Moderator

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    Pretty sure the 70 kWh is post margin.

    53 kWh x 1.31 = ~70kWh
     
  13. PokerBroker

    PokerBroker Member

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    Not if there are less cells
     
  14. dpeilow

    dpeilow Moderator

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    I'm also thinking less cells.
     
  15. JRP3

    JRP3 Hyperactive Member

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    #15 JRP3, Dec 26, 2014
    Last edited: Dec 26, 2014
    First, wow that they are doing an aero and tire upgrade as well. Second, even with that, 380 ish miles from 70kWh = 184 wh/mi, which is pretty amazing, depending on what speed they are assuming. For those familiar with the route what is a reasonable average speed for that trip?

    Oh, I just saw this part:

    Well you can do the same with Roadster 2.0 at 18 mph too...
     
  16. Stoneymonster

    Stoneymonster Active Member

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    Speeds are quite high on the I5 portion of route, figure 80-85mph unless you like driving between two semis. There is a significant climb at the end before dropping down into Santa Clarita before LA. It will be interesting how they plan their drive.
     
  17. jdevo2004

    jdevo2004 Member

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    Looks like the cells are going to be Samsung INR18650-29E. 3.6V 2.85AH, 1C continuous, 3C discontinuous. The cells being used in the Model S require a higher degree of thermal management than the cells currently used in the Roadster so are unlikely to be suitable for the Roadster. The Samsung 29E is well suited for less thermal management situations like in the Roadster.
     
  18. Jackyche

    Jackyche Member

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    I've driven that route quite a few times with ICE. Speed limit is 70, maybe even 75. You'd get murdered rolling in 55mph on rural California highways.
     
  19. Doug_G

    Doug_G Lead Moderator

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    Less thermal management??? Roadster regulates the cell temperature much more aggressively than Model S. It limits pack temperature to 40C whereas Model S lets it go to 60C. The Model S cell chemistry has a higher operating temperature.
     
  20. JRP3

    JRP3 Hyperactive Member

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    Not sure why you think they'd us a Samsung cell when they can get better cells from Panasonic, plus the fact that the cell you specify doesn't meet the posted specs from Tesla.
     

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