Electric only at 85kmh?

Discussion in 'Prius v Technical Discussion' started by jonb505, Oct 8, 2012.

  1. jonb505

    jonb505 Member

    Joined:
    Sep 2, 2012
    317
    77
    0
    Location:
    Vancouver, BC
    Vehicle:
    2012 Prius v wagon
    Model:
    N/A
    Have had my v for just over a month now, 6500km on it. Being my first Hybrid vehicle i've ever owned, I'm starting to get used to how it routinely operates. At this point i figured I had seen it all but this car never fails to surprise me with little things it does.

    So yesterday i was driving along the highway at 100 kmh with cruise on. I had the energy display showing on the display audio. Up ahead there was construction work going on so the speed limit was 80kmh. I slowed down to 85 kmh and put the cruise back on at that speed. the Battery charge showed one bar below full. it was a slightly downhill grade but the cruise kept the throttle about 3 bars above the regen line. I looked at the energy display and it showed engine was still running but was not charging the battery, powering the motor or driving the wheels. I only assumed it was running as the EV light did not come on. And heres the part I could not believe, the electric motor was driving the wheels and drawing power from the battery just as it does in EV operation. So in effect it was running EV with the engine running at 85 kmh. Fastest I've ever seen the car in EV mode has been 71 kmh normally driving the in the city.

    My guess is because of the batteries high state of charge it wanted to expend some of the excess energy. Perhaps the engine has some part in burning off that excess energy, maybe it was in engine braking mode. Or the engine could've just happened to be staying on to keep itself warm(it was a windy day and +15*C outside). I've done some reading on how the HSD operates but seems i still have so much to learn. :confused:
     
  2. Canmore

    Canmore New Member

    Joined:
    Oct 8, 2012
    1
    0
    0
    Location:
    Canmore AB Canada
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    My maximum EV speed has been approx 105 km/h along the Trans Canada Highway between Calgary and Canmore.
     
  3. jonb505

    jonb505 Member

    Joined:
    Sep 2, 2012
    317
    77
    0
    Location:
    Vancouver, BC
    Vehicle:
    2012 Prius v wagon
    Model:
    N/A
    hey canmore, did the ev light actually come on or was the engine still running and not providing drive power like i described above? I thought the system was hardwired to switch to engine power after 72kmh(45mph). From my understanding this would be to protect the battery pack because of its size, which would probably get drained pretty quick trying to propel the car at higher speeds than that. I know the engine will cutoff fuel as it does even in normal cars when coasting but actually propelling the car on electric power alone at such high speeds, does this actually happen at higher speeds with the right circumstances or am i misinterpreting what the energy display is telling me?
     
  4. ItsNotAboutTheMoney

    ItsNotAboutTheMoney EditProfOptInfoCustomUser Title

    Joined:
    Jul 18, 2009
    2,287
    460
    0
    Location:
    Maine
    Vehicle:
    2010 Prius
    Model:
    II
    High-speed glide

    The 72km/h speed limit is to limit the maximum rpm of a motor to 10k.

    However, under certain circumstances where you don't really need the engine the Prius will figure that it's better to use some energy from the battery to spin the engine and limit the motor rpm, rather than burn gas to idle the engine.