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Regenerating while accelerating

Discussion in 'Gen 2 Prius Technical Discussion' started by ghatid, Jul 26, 2007.

  1. ghatid

    ghatid Junior Member

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    Sometimes when I'm driving my car, it gets hard to go into electric mode. I assume this is becuase the car is warming up so it prefers to keep the engine on? The problem is, even when I'm accelerating, I often see that the engine is charging the batteries. This seems kind of silly for me. Is it normal? Why would you want to charge the batteries (especially if they are almost full) if you're also trying to accelerate, even after the car is warm. Sometimes, I have to really step on the gas in order to make the motor work with the engine (instead of against). Does this happen to anyone else? Thanks for any input.
     
    #1 ghatid, Jul 26, 2007
  2. Danny Hamilton

    Danny Hamilton Active Member

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    <div class='quotetop'>QUOTE(Ghatid @ Jul 26 2007, 04:26 PM) [snapback]485704[/snapback]</div>
    Yes this happens. No, it isn't just your Prius doing this.

    It may seem counter-intuitive but the fuel efficiency and emissions indicate that this works.

    There is no need to "make the motor work with the engine". Accelerate hard if you need to, accelerate gently if the situation calls for it, let the car figure out what use of the ICE and MGs work best for the situation. I'm pretty sure you get better MPG by avoiding the use of the battery as much as possible, so forcing use of the battery/MG for propulsion isn't necessarily improving fuel efficiency.

    Keep in mind that, because of the PSD, whenever the ICE is providing propulsion it is also providing torque to both MGs. That torque can either be used to spin the MG and generate electricity, or electricity can be sent to the MG to resist the torque, this is how the Prius accomplishes it's "eCVT" without actually changing any gear ratios.
     
    #2 Danny Hamilton, Jul 26, 2007
  3. efusco

    efusco Moderator Emeritus
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    That's how the car works. Extra energy generated during acceleration is put into the battery for later use. Remember that the ICE tries to run withing a relatively narrow rpm band for peak efficiency.

    If SOC of the battery is below 60% some charge from the ICE will go to the battery, if it is above 60% usually some charge will go from the battery to help propel the vehicle.

    Think of the battery as a big buffer...or like one of those need-a-penny-take-a-penny/have-a-penny-leave-a-penny things. Regen from braking only recaptures a small amount of the charge that goes into the battery.
     
    #3 efusco, Jul 26, 2007
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