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Performance Regen vs. 85 kWh Regen

Discussion in 'Model S: Driving Dynamics' started by KBF, Aug 6, 2012.

  1. KBF

    KBF Model S 2017

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    Does anyone know if the amount of regen is the same in the Performance vs. regular? I tried searching threads to no avail. I may be wrong since I'm no engineer, but the way things are worded on Tesla's Model S "specs" page, the inverter is used for regen, or associated with it anyway. Theoretically this means that the Performance could do stronger regen than the standard model since it has an upgraded inverter, correct? Or is the limiting factor the battery? Has anyone driven both and noticed any difference (or asked engineers who know)?

    I love the regen on my Zero DS, and wish it was stronger, and I'd love as much as possible on my car. And I'd love to have a real, practical reason to upgrade to the Perf!
     
  2. Jason S

    Jason S Model S Sig Perf (P85)

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    Sorry, it really should be the same. I've read folks say that the regen felt weak, but when asked the Tesla folks said it was as much as possible.

    I'm pretty sure it is because of the large mass a Model S carries -- just don't feel the regen because there is so much weight to slow down.
     
  3. VolkerP

    VolkerP EU Model S P-37

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    Regen is limited to 60kW power fed back into the 85kWh battery pack. We don't know if the smaller packs will have even less regen. The Roadster power gauge goes up to 40kW regenerated power. With Model S at nearly twice the Roadster's weight, there is twice the kinetic energy to deal with but only 50% more regen power. That will limit max regen deceleration to 2/3 of Roadster max regen deceleration.

    In addition to that, Tesla smoothed the curve when regen kicks in. In the Roadster, regen jumps to 100% as fast as you lift the foot off the accelerator pedal. Not so in Model S. There is a short delay during which regen is building up. I don't know the length of the delay. But a quarter of a second would be enough to make the transition feel much softer. That was Tesla's design intent and they succeeded.
     
  4. KBF

    KBF Model S 2017

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    So the consensus would be that the 60 kW max regen is due to the battery capacity?
     
  5. Todd Burch

    Todd Burch Electron Pilot

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    Several Tesla reps have mentioned that, yes. Again, take it with a grain of salt, as we've heard conflicting information from reps in the past.
     
  6. wycolo

    wycolo Active Member

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    > So the consensus would be that the 60 kW max regen is due to the battery capacity? [ KBF ]:

    I suspect a combination of motivations to reduce 'Regen Surprise' yet still try to maximize overall regen energy recovery. Best seen in the Roadster when under cruise control driver accidentally hits brake pedal with boot. Max regen is instantly applied, and if you happen to be on a curve or (aargh) on packed ice, the rear wheels could lock up. You would definitely be at the mercy of Traction Control in this situation. I can't wait for winter to find out. When intentionally kicking out of CC, I've learned to bring up the accel pedal beforehand to smooth the transition.

    On the Performance S (I believe my Test Drive was in a Perf S) the Regen Effect is muted as reported here. Too bad on the Test Rides they did not hand us poop sheets for the exact car we were driving- for future reference such as this.
    --
     
  7. Robert.Boston

    Robert.Boston Model S VIN P01536

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    Someone in a test-drive measured the deceleration during regen; it appears that Tesla capped regen at -0.15g, rather than at some specific kW rating, for most of the relevant range.
     
  8. KBF

    KBF Model S 2017

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    This is important info. I guess I'm basically looking for the limiting factor; in Tesla's case right now that means the limiting factor is (due to software) the deceleration. In the future theoretically this could change. If the "hardware" limiting factor right now would be the battery size, then if one would upgrade 8 years down the road to a larger pack (and/or different chemistry) then would the inverter be the limiting factor? I suppose this discussion could also apply to performance in general.
     
  9. Johan

    Johan Took a TSLA bear test. Came back negative.

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    I agree important to know the bottle necks. My take is that we know he big battery can take 90kW of charge (supercharger) so regen could be 90kW BUT we also know that a lot of supercharging will cause premature degradation, so having that strong regen would also probably cause to much degradation. I'm not sure if short bursts of 90 kW (regen) is as harmful as extended infkux of 90kW (supercharger) but many short bursts of regen will quickly sum up to a lot of minutes and hours...


    Sent from my iPad using Tapatalk HD
     

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