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Maximum regen amps

Discussion in 'Roadster' started by asgard, Nov 24, 2015.

  1. asgard

    asgard Member

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    Hi folks,
    The maximum regen amps I am seeing on my Roadster is 83 amps when driving at 60-70mph on a level road and letting go of the accelerator pedal.
    Is that in the normal range. I recall seeing over 100 amps at one point but maybe I am not remembering correctly?
     
  2. BartJ

    BartJ Member

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    Tried this morning on the highway.
    84 amps is the max I had.

    PS: road was wet and I have my winters on
     
  3. Stefan T

    Stefan T Member

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    I had 82A today with heat on in the coupe

    Winter tires and wet road here to
     
  4. asgard

    asgard Member

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    Wet road should not matter unless traction control came on.
     
  5. Mark77a

    Mark77a Member

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    If that c 84 amps is at c 400v its over 33.6 Kw ! ... which is in 3-phase, rapid charging territory !

    iirc the Roadster charging/regen system uses the motor windings in a clever way.
     
  6. dpeilow

    dpeilow Moderator

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    Peak power for a few seconds though - a different beast to sustained power over an hour.
     
  7. gregd

    gregd Member

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    A different vehicle, but I read somewhere about a guy who recharged his Leaf by towing it behind a pickup truck... Probably not a good idea.

    A question, though: Where are the measurements taken? Is the LCD display measuring the net going into/out of the battery itself, or is it measuring where else? Same question for the analog meter on the 2.0/2.5 models? I.e. if you are regenning, say, 5kw on the analog display, but have the heat + AC on max, would the digital display net out to about zero?
     
  8. asgard

    asgard Member

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    I am not sure the LCD displays net current. When I have the headlights on and heater or AC on, it barely registers 2A.
     
  9. hcsharp

    hcsharp Active Member

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    I can get 9A with the heater, AC, and headlights on if it's cold outside.
     
  10. Marius

    Marius Member

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    The LCD displays the current going in our going out the batterie.
    Full regen is indeed 33 kW, with 400V counts for 82A.
     
  11. hcsharp

    hcsharp Active Member

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    Then why do I often see the kW meter go to -40 on my 2.5? Are you saying that the motor might be generating 40kW but what's going into the battery is only 34kW? Perhaps the overhead of the electronics are only 85% efficient?
     
  12. m0rph

    m0rph Member

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    I believe Tesla stated 80% (IIRC).
    I also see around 34kW on my 2.5
     
  13. gregd

    gregd Member

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    I thought that 80% included the battery itself and heat losses therein, i.e. net effect on range due to regen. The meter is in front of the battery, so you're measuring what goes in, not what gets stored. The electronics themselves should be much better than 80%, no?
     
  14. BartJ

    BartJ Member

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    today the SC installed new brake discs and pads and now regen goes up to 98a.
    versus 84a max last week with the old brakes...
    new brakes = less friction = more regen ?
     
  15. sethr

    sethr CPO Roadster #1089

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    I just saw a brief peak of 93 amps, (same old discs/pads, but pretty new AD07's). Usually it's more like 86 - 89 amps max.
     

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