ICE in EV Mode

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by PiPLosAngeles, Nov 28, 2012.

  1. PiPLosAngeles

    PiPLosAngeles Senior Member

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    I started the morning commute with a fully-charged battery and the PiP started in EV mode as expected. Because of the discussion in the "Calculating EV Range" thread, I was watching the EV very carefully when I got near the 17.9 mile mark where I ran out of EV yesterday. I still had 4 miles of EV range left according to the display. In fact, I drove the full 21.5 miles and the PiP was still in EV mode when I got to the garage. The weird thing is that the MPG on the display was only 400 instead of 999. I looked at the consumption graphs and all the bars were to the top all the way across except for one bar that was about 1/16 of an inch below the rest (somewhere around the 80 or 90 mpg mark).

    Does the ICE kick on during EV mode with all accessories off (no fan, no defrost, no heat, no A/C, no nothing)? The ICE was on last night so it couldn't be that it had been too long since the ICE had run. I want to avoid whatever triggered the ICE, but after reviewing the FAQ I don't see anything that applied to my situation. The only thing I can think of is that the ICE was triggered at some traffic light or the freeway onramp and I didn't notice. Does EV mode still allow ICE assisted acceleration?

    [​IMG]
     
  2. benalexe

    benalexe Member

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    Wow how did you get so much? I only get about 9.6 in ev mode
     
  3. PiPLosAngeles

    PiPLosAngeles Senior Member

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    It's downhill most of the way and on the freeway there are a lot of slow trucks I can follow at 55 - 60 MPH without driving everyone nuts.
     
  4. mmmodem

    mmmodem Senior Taste Tester

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    Those two sentences contradict each other. Are you out of EV or not? How can you be out of EV and have 4 miles left on EV.

    To answer your question, yes, the ICE can come on in EV mode.

    1. when you go above 62 mph or
    2. you press on the gas pedal hard enough

    I doubt you were going anywhere near 62 mph since your EV range is way above average, so my guess is that you stepped on the gas pedal a little too hard and the ICE kicked in to give you extra power.

    If you go slow enough, you can get a lot longer distance than the advertised 11 miles. I was in bumper to bumper traffic one time going some 10 mph and EV lasted me about 20 miles.
     
  5. PiPLosAngeles

    PiPLosAngeles Senior Member

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    There's no contradiction. Yesterday I ran out at 17.9 miles. Today when I reached that very same point I had 4 miles left.

    That sucks if the ICE can come on in EV mode. I had assumed EV mode meant what it said, not EV mode unless ICE mode. I wonder if there's a way to modify the system so that EV means EV and not sort of EV.

    EDIT - I'm thinking a toggle switch on the power to the fuel pump might be the easiest solution.
     
  6. john1701a

    john1701a Prius Guru

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    Assuming absolutes is always a red flag.

    Exceeding capacity by the degree you are, it's no suprise the engine starts. Prius is designed to protect the battery. Firing up briefly to help handle the load you are putting on the system makes sense.
     
  7. PiPLosAngeles

    PiPLosAngeles Senior Member

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    A toggle is just that. Either it's on or it's off, not sort of on or sort of off. Otherwise it would be something like "Prefer EV" mode.

    I think it's important to note that the ICE had to have been started very early in the trip when there was plenty of battery capacity. If Toyota designed the traction motor in such a way that it could damage a full battery when ICE is unavailable, that's poor engineering. It would make more sense to have an upper voltage/current limit instead of relying on assumptions that may or may not be true.
     
  8. john1701a

    john1701a Prius Guru

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    When would the ICE not be available?

    Prius is designed to be an extremely efficient plug-in hybrid, not an EV.
     
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  9. 34Hupp

    34Hupp 1934 Hupmobile - Americas 1st Aerodynamic

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    Do you get a chance to charge at your destination? I would be very interested in the performance that you get on the return trip "mostly uphill", and more importantly, what the entire round trip performance is.
     
  10. PiPLosAngeles

    PiPLosAngeles Senior Member

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    No chance. I have hunted high and low on all 8 floors of the parking garage for a single outlet. None. My employer is emphatic that they're not going to add any EV charging stations.
     
  11. 34Hupp

    34Hupp 1934 Hupmobile - Americas 1st Aerodynamic

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    So, with no EV available, what type of performance do you see on that return trip "uphill"? Also, ever thought about not charging for your trip to work and seeing what the HV preformance would be "downhill"?
     
  12. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    Since there are so many special conditions that can cause the PIP to "automatically" turn on the ICE when the EV mode light it lit, it is best to think of the EV/HV toggle button as a "prefer EV" button.

    Accelerating too hard, running out of battery capacity, going faster than 62 mph or going 124 miles since last ICE operation are at least 4 reasons the ICE can turn on.

    But it seems that your explanation is a little odd. If you always keep the car display on that shows your 1 min consumption you'll see when the ICE is on. And it won't be on for just 1 minute (maybe you are looking at the 5 minute display?) Once the ICE turns on it will stay on till the ICE and catalytic convter are warm. The only way to stop this is to turn the car off (when safe) and then turn it back on...it will then be back in EV mode as long as the battery SOC is high enough.

    Mike
     
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  13. PiPLosAngeles

    PiPLosAngeles Senior Member

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    Uphill I get about 51 mpg. I plan on trying HV downhill after a few runs of EV to get a baseline. Whichever way yields the best overall mpg is the way I'll operate, of course. I wish there was a good interface to the car so we could download performance data to analyze by computer for optimal strategies. Unfortunately, we're left with trial and error. At least we can share our experiences via this community which should speed the process.
     
  14. PiPLosAngeles

    PiPLosAngeles Senior Member

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    I'm as certain of the one bar in the 1-minute display as I am that I'm typing this right now. I'll go back and see if I can still pull it up and take a picture.

    EDIT - Nope. I really wish the Prius had a history function with past trips. When 32 GB of flash RAM is less than $20 you'd think it would be possible.
     
  15. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    The PiP is marketed as a very efficient hybrid with some plug-in capacity added. In contrast, the Volt is marketed as primarily an EV with a (not-so-efficient) ICE added to extend the range. Thus, the PiP is not designed to avoid the ICE at all costs; it is designed to use a combination of the electric motor and ICE in the most optimal way.
     
  16. PiPLosAngeles

    PiPLosAngeles Senior Member

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    If the car is going to decide how best to juggle EV and HV, what is the point of giving us buttons to override that logic if they don't really override that logic? Buttons that don't do what they say are more irritating than a lack of buttons because it's patronizing the user. "Here's a button that doesn't do much just so you'll shut up."
     
  17. usbseawolf2000

    usbseawolf2000 HSD PhD

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    The EV icon above the HSI bar disappears (only the border of the icon left) if the ICE kicks in. That's how you can tell.
     
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  18. bisco

    bisco cookie crumbler

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    i like the ev button because it prevents the ice from firing if you stay within the parameters set forth in the manual. otherwise it would be a regular prius with a larger battery and the ice would fire as soon as i back out of the garage like my 08 did which i hated.
     
  19. PiPLosAngeles

    PiPLosAngeles Senior Member

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    How much pressure (pounds, kilos, degrees of travel?) on the accelerator does the manual state will trigger the ICE in EV mode? Sorry, I'm in the office and the car and manual are in the parking garage a block away. I'd like to fashion a device to prevent the accelerator from traveling past that point.
     
  20. bisco

    bisco cookie crumbler

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    it doesn't. you have to watch the hsi. if it crosses into te power zone on the far right, the ice will fire. it's pretty easy to stay out of it after you practice a bit. especially when cruising. accellerating hard, trying to get the most out of the battery without crossing the line is a bit more difficult and might horten battery life if done persistantly.
     
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