Ev / HV Question

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by benalexe, Oct 2, 2012.

  1. benalexe

    benalexe Member

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    So this morning I left my home for a 2.5 mile drive. Since I was going to be using the car later today and not able to charge I decided to drive the 2.5 miles in HV mode to save the EV later. When I left my home my ev miles left was 11.0. When I got to my destination the EV miles left was 9.0. I was under the impression if I took the car off EV mode then it would not use the EV part of the battery and save it for when I turn it on. If I am correct then why did the EV millage range go down'?
     
  2. It happens all the time, you can't do anything about it. The main thing is that in order charge EV some more some quantity of of EV must be saved. How much? I have gone done to .2 miles, and it still charged up in HV fine.
     
  3. Electric Charge

    Electric Charge Active Member

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    I learned that the hard way as well (wanted to do the same thing for the same reasons). I'm no expert, but this is what I have learned in the last week or so:

    From what I can tell, you have to look at it this way: EV mode allows you to drive at higher speeds as long as the traction battery can support it, and won't use the gasoline engine unless you accelerate/drive fast, while HV mode will use the traction battery as much as possible to improve mileage, instead of letting the battery just sit there fully charged (plus HV will also turn off the gasoline engine if you are cruising at lower speeds, at least in ECO mode, and I'm guessing it will cruise a lot longer on battery due to the added battery capacity).

    As far as I can tell, there is no way of stopping this behavior.
     
  4. benalexe

    benalexe Member

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    Sorry not sure either of you answered the question. Let me try and re-word. I charge the EV fully.... I turn on the HV mode so in a sense the car is acting like a regular prius not an EV... However the EV millage still declines when not in ev mode.

    Why?
     
  5. priuskitty

    priuskitty PIP FAN

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    because there's only one battery for both EV and HV, so when you go into HV mode some of the EV is allotted to HV, that's my guess
     
  6. LenP

    LenP Member

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    This is a very good question. It really shouldn’t happen. It deserves an answer from Toyota! It might be a computer glitch like when the blower comes on it lowers the EV mileage by the same amount as if you were running full AC!
     
  7. rogerv

    rogerv Senior Member

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    Maybe this is over-simplifying, but if you think of the PiP in HV mode as working the same as a regular Prius, you will realize that some juice is being drained from the battery as long as there is some available, depending on the need to supplement the ICE. If you drive long enough in HV mode, the battery will gain some charge from normal regeneration.
     
  8. Jimbo69ny

    Jimbo69ny Active Member

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    Rogerv is right. Keep in mind that no matter what, EV is used when ICE is started for the first time, as it warms up.
     
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  9. fotomoto

    fotomoto Senior Member

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    OP, what was your ambient temperature this morning?
     
  10. Only Toyota knows the whys and wherefores, and sometimes, even they may not be so sure!
     
  11. Rebound

    Rebound Senior Member

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    First, I think your problem may be user error: Every time you start the car, it engages EV mode, if there is sufficient charge. So if you turn EV mode off and shut the car off, it will start in EV.

    I drive about two miles before getting on 40 miles of freeway. I sometimes switch to HV mode on the freeway. The EV range remains until I restart the car or switch to EV.
     
  12. rockfeller

    rockfeller Junior Member

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    Let add an observation here: you may agree or not
    When you completely deplete your EV battery, PiP will no longer go into EV mode even if you press EV button.
    If you continue to drive in HV mode, regenerative braking add charge to battery, indicator shows battery is full(all bars ), but an equivalent EV miles will not be displayed.

    My understanding is, HV mode uses EV battery without permission, and EV battery will continue to show correct EV miles until it reaches 0.0 miles. After that regenerative braking in HV mode for some reason does not feed the number back even though the battery indicator show a full level of charge.

    Yes , it should be clarified from Toyota, why this incomplete one-way battery charge indicator ?,
     
  13. benalexe

    benalexe Member

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    abou 60 degrees
     
  14. rockerdan

    rockerdan PiP Rocks!

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    ^ If you go down a long decline the EV miles DO come back, but only on a long regen.

    As stated in above posts...when put into HV starting off the bat with full charge, the car will use some EV range/battery. Its been my experience that it will use a certain amount then EV range will remain at a certain point. I dont think it will continue to use EV range/battery if you drove far enough in HV. And I have seen EV miles come back up when driven in HV long enough at higher speeds.

    Dan
     
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  15. benalexe

    benalexe Member

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    Correct.. Just got back from my trip today I started about 11.4 HV miles and it ended up dropping to about 9 where it remained the entire day.
     
  16. John H

    John H Senior Member

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    I think it is probably best to consider 2 of the EV miles as also being the HV buffer, about 500 watts.
     
  17. rockerdan

    rockerdan PiP Rocks!

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    another thing I noticed a few times...

    when in HV mode and EV range is down near .1 , The battery does not deplete as it does when EV range is full on takeoff in HV. And i have seen EV range add back on when this low.

    Dan
     
  18. rockfeller

    rockfeller Junior Member

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    Good to know its not a bug.
    Thanks for explaining this.
     
  19. El Dobro

    El Dobro A Member

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    Interesting, I was going to ask about this, too.
     
  20. What is fun to do on a long trip, ( anything exceeding your EV range ) look for a flat or decline, put the car in HV, then after the engine is off, keep the car in HV to increase the stored EV charge. Climb hills in EV = 100+ mpg then drive in HV again on downhill and flats. During this portion one can attain 100 mpg or certainly 50-100 mpg on the instantaneous mpg readout. When finally getting home or chargepoint try to use all EV again ( equals 100 mpg plus )
     
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