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Should battery charge while coasting?

Discussion in 'Gen 3 Prius Technical Discussion' started by Mobius, Nov 11, 2009.

  1. Mobius

    Mobius New Member

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    I noticed that when taking my foot off the accelerator and coasting, the hybrid display indicates a bar to the left, as it does when braking, although to a lesser extent. Is this normal? I thought that the battery gets charged just on braking....
     
  2. chrisj428

    chrisj428 Active Member

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    Mobius,

    If you have removed your foot from the accelerator pedal, the vehicle will begin to regenerate electricity. While coasting, there will be some wind-down (as with any vehicle). Light application of the brake pedal will increase this effect.

    Having said that, there is something I've seen referred to as pulse-and-glide. It seems to be a hypermiling technique unique to the Prius whereby one accelerates to speed and then, on a level surface, applies just enough pressure to the gas pedal to disable any regenerative braking, but not enough to request motive force from the electric motor. This is indicated on the screen by a complete absence of any arrows whatsoever whilst moving. I have never seen it personally, but I'm not much of a hypermiler.

    So -- to answer your original question: Yes. It's normal. :D
     
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  3. john1701a

    john1701a Prius Guru

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    When you step on the brakes, the big traction motor turns into the capture device. You do indeed get electricity regenerated that way.

    There's also a smaller motor. That's the one at play when you haven't stepped on the brake yet. It's what generates electricity as you drive. Normally, that energy comes from the engine. But when slowing, it can come from the road instead... which is what you were seeing.
    .
     
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  4. hobbit

    hobbit Senior Member

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    Search this for the phrase "no
    feet on the pedals" ...
    .
    _H*
     
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Note that in N, you really are coasting, and no regen is taking place. While I would prefer that that be the same as lifting off the gas pedal, the default of regen is more 'normal' for folks used to any other car.
     
  6. qbee42

    qbee42 My other car is a boat

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    The small amount of regenerative braking that occurs when you lift your foot from the accelerator pedal is intentional. It mimics the engine drag found in normal cars. Toyota engineers have endeavored to make the Prius feel and drive as much like a normal car as possible.

    Tom
     
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