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HV using EV capacity

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by john1701a, Apr 9, 2012.

  1. andyprius

    andyprius Senior Member

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    When not actually using go pedal, is everybody still keeping thier foot lightly on the brake? and is the regen noticeably better?; as demostrated with previous generations?
     
  2. ryogajyc

    ryogajyc Active Member

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    I've been trying to deplete the HV battery range after EV miles is exhausted and it automatically switched over, but I find that it is kind of hard to. Any tips on how to do this? I usually end up at my destination in HV mode with 6+ bars and I would like to end the trip closer to 0 bars. I'm a little surprised that the HV range seems to be so large and that it isn't possible to more aggressively use that energy until the HV range is almost depleted.
     
  3. LenP

    LenP Member

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    The ICE makes sure you never run out of charge. Without it the hybrid mode wouldn't work, it keeps the battery charged. The PIP has one big battery, a larger percentage is for the EV mode the rest is for the HV mode and some is never used, it's a buffer to keep the battery healthy.
     
  4. john1701a

    john1701a Prius Guru

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    6 bars without any "miles" is exactly what you should have. That's proper hybrid (no plug) operation. 0 bars would be bad... and next to impossible to actually do, since the system protects against deep-discharging.
    .
     
  5. iRun26.2

    iRun26.2 New Member

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    I think it is optimal to end with only three bars of battery left in HV mode just prior to a charge. If you drop to two bars the ICE will turn on and charge the battery to five bars (which can unexpectedly reduce your trip's mpg). If you want to drive more (before cord charging) then I wouldn't want to stop with only three bars. I try for three (or four) bars since I know I'll charge before my next drive. I use all the charge the car lets me use (and I'm glad I don't have to worry about getting the charge level too low...at least I hope I don't).
     
  6. 9G-man

    9G-man Senior Member

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    I'm not completely following the desire to intentionally deplete HV battery capacity. That deminishes overall hybrid efficientcy, as it would in a normal Prius.
    Such a habit might only be applicable if you were to cord-charge right after you did it.
    The only way you could do it is to stealth below 46 MPH, in perfect circumstance that ended at your charging location.
    Next to impossible to accomplish, because HV mode is designed to maintain a certain level of battery capacity.
    Please explain.
     
  7. seilerts

    seilerts Battery Curmudgeon

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    I don't know if anyone has tied bars to SoC yet...but in a regular Prius, you could get maybe half a mile, if already moving, depleting from 6 to 4 bars. If you will be charging at the other end, take it. Otherwise, stay at 6 bars, lest the car run the engine to maintain SoC.
     
  8. ukr2

    ukr2 Senior Member

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    Trip Comparison: (using above table of results)

    Tuesday - Used EV mode that auto-switched to HV when Battery depleted
    Wednesday - Started in EV, then manually switched to HV, then switched back to EV when GPS Distance to Destination was equal to the Battery Miles.

    Tuesday - Battery started with 10.5 miles, got to work with Battery at 0 miles and in HV mode. Charged before and after lunch. Then with Battery at 10.5 miles, got home with Battery at 0 and in HV mode.
    Total Miles= 32.2, Cons.MPG=199
    added 4.07 kWh Charge at work
    25 EV miles and 7-8 HV miles

    Wednesday - Battery started with 10.5 miles, manually used EV, then HV, then EV mode and got to work with Battery at 3.2 miles still in EV mode. Charged before and after lunch. Then with Battery at 10.5 miles, manually used EV, then HV, then EV mode and got home with Battery at 1.0 still in EV mode.
    Total Miles= 32.4, Cons.MPG=116
    Battery had 4.2 miles to spare
    Only added 2.99 kWh Charge at work
    16-17 EV Miles and 16-17 HV miles

    Both to and from work on Wednesday, I should have switched from HV to EV earlier. I gained more Regen miles in EV mode than expected.

    I also wish the EV Driving displays all had 1 decimal place.
     
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  9. ryogajyc

    ryogajyc Active Member

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    By closer to 0 bars, I meant something like 1-2 bars not 0 bars. I didn't have a Gen3 Prius, so I don't have a feel for what they represent other than my experience with a Gen2 and was being intentionally vague. I'm not trying to deep-discharge the batteries, but it does seem like the Plug-in leaves some charge that could be used.

    By "ending at my destination" I meant "ending at my destination where I can charge".
     
  10. Piprius

    Piprius Member of the cult of Prius

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    I am curious about how the EV/HV miles are recorded on the energy display screen. Perhaps someone (/cough john /cough) who resets their energy display every trip can answer this.

    If one is in HV mode but drives slow enough that the engine is off and you are actually using the battery, are these miles recorded as EV or HV miles?

    Basically, are miles recorded as EV miles only if in EV mode, or are they recorded as EV miles whenever the gas engine is off and you are drawing from battery?

    I am trying to make sense of why my HV mpg are higher than others and am curious if a possible reason is since I do a fair bit of HV driving with low speed "EV" usage that these miles might be erronously being recorded as HV miles, upping my HV milage.

    Only other thing I can think of is that since I do drive some distance in HV, the engine has time to heat up and I avoid the "short trip" HV mpg death.
     
  11. john1701a

    john1701a Prius Guru

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    When the EV symbol is illuminated, it's counted as EV, regardless of mode.

    That's why you can Just Drive It without having to be concerned with button pushing.
    .
     
  12. TPinho

    TPinho Junior Member

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  13. TPinho

    TPinho Junior Member

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    Sorry, I don't know attached pictures.
     
  14. mikenewmediary

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  15. Piprius

    Piprius Member of the cult of Prius

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    Are you certain? In my very limited "test" I had used 8 EV miles yesterday and when I started using EV mode today I still had 8 EV miles displayed. I had "used" 2-3 miles of battery whilst driving in HV mode.

    Perhaps I mis-remembered but just to be certain John have you seen the EV display go up using on HV mode?

    Just to be clear, I know that EV usage in HV mode is doing EV. I am wondering specifically about the energy screen reporting EV miles.
     
  16. bilofsky

    bilofsky Privolting Member

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    So what's the bottom line? Switch into HV when there's 0.1 miles of EV left?

    Or Just Drive It?

    (Some of you may be smarter than the PIP. But I suspect the energetic little sucker is smarter than I.)
     
  17. john1701a

    john1701a Prius Guru

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    I wasn't then. Turns out, my gut was right and my hypothesis was wrong. Driving 188 miles today confirmed it.

    All driving was in HV mode. At least 4 miles were with the "EV" symbol illuminated (confirmed by 0 RPM on the ScanGauge). Despite that, none were counted as EV. The ratio screen counted the entire distance as HV.

    That means EV is only when in EV mode.
    .
     
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  18. Piprius

    Piprius Member of the cult of Prius

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    Hmm, then this will explain why my HV ratio is higher than others on the MPG spreadsheet. I save my EV for later in the day, and so I am using EV power in HV mode, all of which is counted as HV mileage. I am assuming that most people o. The spreadsheet are using their EV out the door, and thus don't have as much EV power available when doing HV mode, and thus lowering their apparent HV mileage vs. mine.

    Thanks for testing this John. Good to know how the energy display screen is reporting data.

    Unfortunate that EV miles regardless of mode are not reported as such. This could alter the display values significantly.
     
  19. ukr2

    ukr2 Senior Member

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    Well that's too bad.
    Why would they do that?
    Therefore, HV miles / Gas Gallons is actually NOT HV MPG.

    John, do you know of any way we can determine the EV miles driven in HV Mode?

    Now, when in EV mode and the Heater comes on and the EV mode display changes to the HV mode display, are these miles HV or EV?
     
  20. seilerts

    seilerts Battery Curmudgeon

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    Isn't what really matters the amount of kWh charged vs. # of gas gallons consumed vs. total miles traveled? i.e. maximize kWh and miles while minimizing gas gallons.

    To put it another way, if you never plugged in the car, then EV miles = 0, since all battery energy comes from ICE in that case. If you toggle back and forth between HV and EV to charge up the battery downhill or coming off the freeway, those subsequent low speed EV miles shouldn't count as EV anyway.

    Respectfully,

    Clausius