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Does the 70D have new batteries and will the 85D become a 100D?

Discussion in 'Model S' started by thegruf, Apr 8, 2015.

  1. thegruf

    thegruf Member

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    The cell maths doesn't really stack up for 70KWh
    So what is this battery?

    And what does it mean for the 85KWh?

    This is kinda putting me off a P85D purchase if I am to find that I just missed out on a 100D
     
  2. mgboyes

    mgboyes Member

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    S85 battery is known (from having been dismantled for salvage) to be configured as

    16 modules each containing 6 banks of 74 cells = 7104 cells, which at [email protected] = 86.9kWh

    S60 battery is theorised to be

    14 modules each containing 6 banks of 60 cells = 5040 cells, which at [email protected] = 61.7kWh

    ----

    A really obvious reconfiguration would be to include 16 of the S60 modules in a pack which would be 70.5kWh.

    This would also mean that the S70D has the same pack voltage as an 85.
     
  3. Kevin Harney

    Kevin Harney Active Member

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    70D implications for the P85D

    Starting speculation on the affects of the 70D on the P85D.

    Assuming that the battery gets increased to 100kWh and based on the differences between the 60 and the 70 I think we could see the following changes in 2016. Elon has stated that we will see no more changes in the Model S this year. However he said that BEFORE the 70D was announced so these may in store sooner than 2016. Also the difference between a 70kWh and an 85 does not really justify the extra size anymore.

    Model S P100D

    Range 302 miles, 0-60 in 2.8 seconds and keep the top speed of 155 :love:
     
  4. sickfox

    sickfox Member

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    P100D? I'm down with that! :biggrin: Then we can truly hang with super cars...
     
  5. 1208

    1208 Active Member

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    P1004WD

    A motor for each wheel meaning better cornering.
     
  6. TampaRich

    TampaRich Member

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    Weight might be a good indicator but it doesn't look like Tesla breaks it down to that level of detail.
     
  7. HVM

    HVM Savolainen

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    That would be P110Q (quad)
     
  8. ThosEM

    ThosEM Space Weatherman

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    How exactly, is that advantageous? Would the torque be varied between left and right in cornering? How does that help?

    I'd have thought that, if the motors are outboard, they would add to unsprung weight. If they are inboard, they have to fit within a narrow space. In either case they seem to increase complexity quite a bit. Maybe it's worth it?
     
  9. Johan

    Johan Took a TSLA bear test. Came back negative.

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    Hate to be a party pooper... but likely curb your enthusiasm. How they got from 60 to 70 kWh was by putting in cells where there was earlier just ballast in the 60 pack. Probably no new chemistry. The 85 pack is already full.
     
  10. mgboyes

    mgboyes Member

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    Agreed. Going beyond 85kWh means a new type of cell, or a larger pack. Neither is going to happen in the near future.
     
  11. orangem

    orangem Member

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    Pure speculation:
    1.the 70kwh is going to be the home power supply preferred unit. Higher economies of scale.
    2. Or perhaps the 70kwh perhaps is the 85 software limited? Assuming the 85 packs achieved a cost that still allows for substantial margin with expected 70D sales volume....
    Less configuration, higher production volume and less switching cost. I would speculate next to go is the RWD config....
     
  12. Saghost

    Saghost Active Member

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    You'd mount them inboard and off axis, just like the current Model S drive motors - instead of a differential in the center, you'd have two transmissions back to back. Twice as many gears, but they can be half the width, and you do eliminate the differential.

    The benefits are substantial - in addition to maximizing every bit of grip for both acceleration and braking (ultimate AWD) and the redundancy to get you home if something breaks, it opens the door to active handling - where they can program exactly how much understeer or oversteer the platform should produce.

    Honda is one of the leaders in active handling - the RLX hybrid has a motor on each rear wheel in addition to the ICE and motor on the front wheels. Here's a review with video of the power delivery it is producing as the car accelerates and decelerates around turns - Autoblog said that they felt it greatly improved the sporting feel of the car:

    2014 Acura RLX Sport Hybrid [w/video]
     
  13. Bulletproof

    Bulletproof Vendor

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    Not that they would, but in-wheel motors, whether the Michelin system or the Protean would add unsprung weight, but you could have complete torque control at any speed, under any circumstances.
     
  14. Saghost

    Saghost Active Member

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    But you can get the benefits without the unsprung weight. :)

    As demonstrated by the C-X75, SLS, and Rimac One, the obvious way to build an electric supercar is with frame mounted motors with reduction gearing driving individual wheels through conventional half-shafts.
     
  15. Saghost

    Saghost Active Member

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    Interesting. I was expecting the other obvious approach - 14 S85 modules = 76 kWh using your math, while eliminating the need to manufacture/stock S60 modules.
    Walter
     
  16. notAmeenPerson

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    I thought it was mentioned somewhere (by Elon, JB, or Panasonic) that there were continual increases of 3-5% in the batteries each year in terms of capacity. If that was the case it would make a capacity increase from 85 kWh possible.
     
  17. Johan

    Johan Took a TSLA bear test. Came back negative.

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    Yes but in reality you'll see step changes let's say every 3 or 4 years where capacity increases, corresponding to an average improvement of 3-5% per year.

    I'm not saying it's impossible that there's a new chemistry in the 70 kWh cars, Im just saying to me it's very unlikely and the explanation I suggested above (just filling up the pack more) is way more likely to be true. Occam's razor and all that...
     
  18. AndreyATC

    AndreyATC Member

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    I like your logic better
    :)
     
  19. thegruf

    thegruf Member

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    That was my thinking too.
    If true they are underestimating hte capacity, probably for marketing reasons as it would be too close to the 85KWh.
    That said, mgboyes config could also work and on balance I rather doubt they are fitting any more batteries than necessary due to the cost.
     
  20. Johan

    Johan Took a TSLA bear test. Came back negative.

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    Having the pack voltages of the 70D and 85 match could be an advantage with regards to motor and inverter control design etc.
     

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