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Hybrid System Indicator/braking question

Discussion in 'Gen 3 Prius Technical Discussion' started by Ispedbyu, Nov 14, 2010.

  1. Ispedbyu

    Ispedbyu New Member

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    While driving and observing the Hybrid System Indicator gauge doing its thing relating to power vs. regeneration, I notice that under deceleration and no braking, the small area marked charge begins to show and does not appear to gain any until a slight amount of braking is applied, which causes the gauge to move more to the left, filling the area marked charge until the brake is released, then returning to a small portion of the area.

    This makes no sense to me, as it would indicate that the brakes are able to generate power back into the system..

    Can someone explain this ?
     
    #1 Ispedbyu, Nov 14, 2010
  2. Britprius

    Britprius Senior Member

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    Braking generates electricity witch is fed back to the battery. The friction brakes only normally work below 7MPH.
     
    #2 Britprius, Nov 14, 2010
  3. jdcollins5

    jdcollins5 Senior Member

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    Also, in an effort to make the Prius drive like a "normal ICE only vehicle", Toyota adds the slight regen in the Charge area to simulate engine drag of an ICE when you let off the accelerator.
     
    #3 jdcollins5, Nov 14, 2010
  4. Paul58

    Paul58 Mileage Miser

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    What they said... Also, I believe the electric motor is actually acting as a generator during these times to generate a small amount of charge, lightly applying the brakes increases the amount of regeneration, applying the brakes further actually applies the brakes...
     
    #4 Paul58, Nov 14, 2010
  5. qbee42

    qbee42 My other car is a boat

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    This is the whole concept of regenerative braking. Regenerative braking takes kinetic energy from the moving car and converts some of it into electricity which is stored in the battery for later use - hence the term "regeneration".

    Normal brakes (friction brakes) take kinetic energy from a moving car and convert it to heat, which is then discarded into the air.

    Tom
     
    #5 qbee42, Nov 14, 2010
  6. fuzzy1

    fuzzy1 Senior Member

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    This statement is too easily misinterpreted.

    Below 7 mph, all braking is friction.

    Above 7 mph, light to moderate braking is normally by regeneration. Depending on speed, moderate to hard braking requires friction brakes in addition to regeneration. And there are some circumstances that use friction brakes only.
     
    #6 fuzzy1, Nov 14, 2010
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