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Steep hill + 0 EV range + Cold ICE = overloaded charger?

Discussion in 'Prime Fuel Economy & EV Range' started by arthur92710, Sep 21, 2017.

  1. arthur92710

    arthur92710 Junior Member

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    tldr: On my way back home from work I run out of EV range right before the top of a very steep hill. My prime switches from EV mode to HV mode, the ICE kicks in and a few seconds later I start to decend the hill.

    This is a very steep hill and it take have to apply pretty much 100% of regen braking not to go over 50mph.

    I've noticed on the Hybrid system display that power only flows from the motors to the battery. There are no arrows going from the engine to the battery. Same on the Energy Monitor on the 11in screen. But the engine is running the warm up cycle so there should be power flowing out.

    Is this a bug in the displays or is the charger already at 100% because of the regen?

    If it's not a bug, should I run the warm up cycle sooner so I'm not losing that energy?
     
  2. john1701a

    john1701a Prius Guru

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    That's totally normal. I've since three hybrid system operate that easy with all 5 generations.

    It simply just consumed all the electricity being generated.
     
  3. arthur92710

    arthur92710 Junior Member

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    Are you sure it is? So then it's a bug in the displays?

    Any idea on how I could verify that the energy from the ICE and the regen is both simultaneously being sent to the battery?

    I'm thinking measure the current flow during 100% regen, measure the current flow during stationary ICE warm up, add together and compare to the total current flowing into the battery during my situation in the first post.

    Does the same OBDII (generic ebay bluetooth type) scanner that worked with my GEN 3 work in the Prime? I haven't tried yet.
     
  4. kevinwhite

    kevinwhite Active Member

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    During engine warm-up it is better to leave the engine unloaded than attempt to extract power from it as a generator. To do so will result in additional fuel consumption at a time when it is operating inefficiently - there isn't unused power available.

    kevin
     
  5. Rmay635703

    Rmay635703 Senior Member

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    Try to crest the hill at as slow of a speed as possible (like 15mph)
    Then allow the hill to accelerate you
     
    priuscatprimeguy likes this.
  6. arthur92710

    arthur92710 Junior Member

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    I'm pretty sure that my gen 3 will send power to the battery when it's warming up. Probably not much but also not an insignificant amount. I would guess that a prime does the same.

    I do when there's no one behind me.
     
  7. Lee Jay

    Lee Jay Senior Member

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    There is no energy from the ICE - it's just idling to warm itself. It's either completely unloaded or mostly unloaded.
     
  8. bisco

    bisco cookie crumbler

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    this strategy will extend the prime engine life beyond that of the hybrid.
     
  9. arthur92710

    arthur92710 Junior Member

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    Problem solved, kind of. I drove over 400 miles for various trips in the Prime this weekend, got home Sunday night with like an 1/8th tank of gas left.
    This morning I took my regular route to work and back and I got through my whole 34 mile hilly commute on just EV range. I got home with 1.4 miles to spare.
    The weight reduction helped out a lot.
    When I got to the top of the hill in OP I had 1.4 miles of range left, it's mostly down hill from there so I got home for free.
    Ill post some pics in a few. Unfortunately I didn't reset my trip counter, I'll to it tomorow.
     
  10. arthur92710

    arthur92710 Junior Member

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    [​IMG]

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    6.2 miles/kwh!
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