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With a steady gas pedal battery keeps switching to electric motor.

Discussion in 'Gen 2 Prius Technical Discussion' started by Solarman44, Oct 5, 2009.

  1. Solarman44

    Solarman44 Junior Member

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    When I’m cruising on the highway at a steady speed my 2004 just started switching back and forth to the EV mode. With the MFD in the consumption screen I just noticed yesterday that the yellow arrow from the battery would come on for a second and then off for about 10 seconds and then back on again, over and over as long as I kept my pedal steady. This happens with blue bars and all the time now.

    I took the car into the dealer today and they “said†they could not find a problem. They claimed to have taken it on the road but didn’t see anything. I told them to keep looking as this is not normal. In the 5.5 years of driving the car this has never happened, has anyone else had this problem??? I really need some advice on this one.

    Thanks,

    John
     
  2. JimboK

    JimboK One owner, low mileage

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    What's puzzling to me is that you haven't noticed it before. This is normal behavior for the conditions you describe.
     
  3. efusco

    efusco Moderator Emeritus
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    Yup, absolutely normal and absolutely not a problem. It's how the car works...it continuously "borrows" energy from the battery and then stores some back in there as the road subtlely fluctuates. That allows it to maintain a constant, efficient, ICE RPM rather than reving and lugging to compensate for energy need or surplus.
     
  4. Solarman44

    Solarman44 Junior Member

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    Thanks everyone for your input. It just worried me that the arrow was doing this constantly at a steady speed and I don't recall ever seeing it do this that much, kind of like a kid playing with a light switch, on and off, on and off.
     
  5. hobbit

    hobbit Senior Member

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    The system in steady-state highway always shuttles a little
    current in and out of the battery, but it's only a couple of
    amps -- just a trickle as long as you're sitting around 60% SOC.
    The arrows don't show you how *much* is going on there, one of
    the long-standing failures of that display...
    .
    _H*
     
  6. uart

    uart Senior Member

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    Hi Solarman. Think of the MG+Battery in this case as acting a bit like a "load leveller". In a normal car the engine has no choice other than to exactly match the power demanded by the current speed, terrrain and accelerator pedal setting - even if it results in it running at an inefficient operating point. In the Prius on the other hand, as the power demand changes slightly the ICE can maintain a more efficient operating point and shunt power either to or from the battery to make up the difference.
     
  7. Sandy

    Sandy Hippi Chick

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    Very normal