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Strange Behavior: EV Mileage Sudden Drop

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by rorystewart, Apr 22, 2014.

  1. rorystewart

    rorystewart Junior Member

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    I was driving up a hill today at about 30 mph with .9 miles remaining showing on my EV battery meter when all of a sudden it drops to 0 EV miles remaining and shows only 2 of the battery level bars (which is very very low), and the engine of course turns on. What happened?

    I promise I did not push the EV power bar over its threshold. I monitor that like a hawk. I also know for a fact that it jumped from .9 to 0, because I watch that part like a hawk. This part of the trip is near the end of my drive home and I've done it about 50 times so far with no issues. With .9 miles left at that point on the hill I have always been able to make it to my driveway with .4 or .5 remaining, so this is very odd.

    Has this happened to anyone else?
     
    #1 rorystewart, Apr 22, 2014
  2. bisco

    bisco cookie crumbler

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    i have seen odd behavior every now and then, but i don't watch it like you and always figure i made a mistake. i wouldn't let one incident worry you. give it a few days and let us know what happens. all the best!(y)
     
    #2 bisco, Apr 22, 2014
  3. bfd

    bfd Plug-In Perpetuator

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    The computer "misoverestimated" your remaining EV range and had to make a quick adjustment? Hill climbing can take an instantaneous toll on EV range - that's been my observation anyway…

    Statistically, it is called normal variation. And it could probably be traced to something you did earlier in the trip today that was just different enough to lose a little juice.

    I swear I drive the same way every day. Sometimes I make it home with several miles of EV to spare, and other days it is not even close.
     
    #3 bfd, Apr 22, 2014
  4. El Dobro

    El Dobro A Member

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    When I leave my house, I go up a half mile long hill. That hill takes a mile's worth of EV.
     
    #4 El Dobro, Apr 23, 2014
  5. GregP507

    GregP507 Senior Member

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    I don't claim to know the answer, but I have seen something similar with mine. I suspect that the Prius holds a certain amount of charge capacity in reserve, so that it can be utilized when additional power is needed. This reserve is normally kept topped largely by collecting regenerated energy from coasting and braking.

    It may have been depleted to the point where the engine was engaged to charge the hybrid battery up to an acceptable level. Since this process is very inefficient (burning gasoline to charge the battery, and then using the stored electricity to power the car) it may have been a relatively rare situation where the engine was needed to charge the main hybrid battery, and therefore showed a significant decrease in mileage.
     
    #5 GregP507, Apr 24, 2014
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