EV vs HV mode

Discussion in 'Clarity' started by peterkronenberg, May 16, 2018.

  1. Maggie

    Maggie New Member

    What would you suggest for my commute?

    My commute in the morning is 30 miles stop and go traffic on the freeway with very brief periods of no traffic. The commute home, if I leave early enough, is 30 miles freeway and maybe 4-5 miles of it stop and go. I can only charge when I get home.

    I'm thinking EV mode on the way to work and HV mode on the way home?
  2. MNSteve

    MNSteve Well-Known Member

    Generally I agree with your strategy, and it depends somewhat on how much effort you want to invest in switching to/from HV.

    My personal goal is to use EV for everything except cruising on the highway. So if I can switch to HV while cruising and this gives me enough EV left for the rest of the trip, that's ideal. The curve ball for you is the stop-and-go. I prefer to run in EV in this case, but depending on the ratio between stop-and-go and straight cruising, you may not be able to do this.

    So the way I would probably handle this is that when I saw that I was in for a nice stretch of no-traffic highway, I would switch to HV. Which of course has the side effect that, based on Murphy's Law, as soon as I push that button traffic will appear.
  3. Maggie

    Maggie New Member

    Yes, just like when I push the cruise control button, traffic appears.

    Would Econ be better for stop and go and some good stretches. My goal is to use as little gas as possible (I'm sure that's everyone else's too).
  4. MNSteve

    MNSteve Well-Known Member

    Depends on your driving style. ECON will tend to discourage unnecessary quick acceleration. If you're already doing that, it will have no effect.
  5. qwerty607

    qwerty607 New Member

    I've had my 2019 Clarity for a few weeks and it has mostly been commuting and all EV mode. This weekend we went for longer trip though and I attempted to use the approach discussed here with EV for city driving and HV for highway driving. The thing that surprised me was how quickly my EV range was depleted while driving in HV mode.

    I started with 100% charge, drove 140miles total, ~20miles in EV mode, and the rest HV mode. My EV range was 0 miles during the last 30 miles. EV range was definitely being used while I was cruising on the highway.

    Is this typical for other Clarity drivers?
  6. Paddy

    Paddy New Member

    It only saves your battery and stays at 57% on HV Charge mode. So if you don’t want to deplete your battery in long drive, you have to set it to HV Charge

    Sent from my iPhone using Tapatalk
  7. KentuckyKen

    KentuckyKen Well-Known Member

    Not typical for me. Last round trip of 200 miles (100 miles each way) I lost only one bar. I started with a full charge and in HV. Returned home and it only took 2 kW to charge fully. A small amount of that was local driving at each end but I kept it in HV the whole time so I could calculate mpg and most of the local was within the blue part of the Power Gauge which I assume is where some of that 2 kW went. I got 50 mpg with no power loss or angry bees.

    Did you make any stops and forget to renter HV mode? The Clarity defaults to EV whenever restarted. I’ve forgotten to reenter HV in several trips. @insightman even tapes an HV label on his Drive button to help remember.
    Edit: I’ve never used HV Charge and all my HV trips mostly conserve the SOC with just small losses.
    stacey burke and 2002 like this.
  8. Chuck

    Chuck Member

    I have never had the EV range go to 0 while on HV mode. As Ken mentioned, if you toggle between EV and HV mode then you will loose EV range since you are 'resetting' the EV range you are trying to maintain in HV mode. I have never encountered a situation where HV Charge Mode made any sense.
    KentuckyKen likes this.
  9. RickSE

    RickSE Active Member

    I was on a 300 mile trip just yesterday. I hit HV as soon as I got on the highway and lost almost no EV miles while getting ~50 mpg on gas. I’m guessing that you forgot to hit HV at some point when you stopped and shut off the car or somehow hit the hv button and shut it off. My drive was pretty flat. No bees (angry or otherwise). The car uses battery at low speeds (I hit some traffic) but then recharged back to original state when I was back up to speed. I saw the gear on the dashboard quite often and the gear + charging occasionally.
    KentuckyKen likes this.
  10. qwerty607

    qwerty607 New Member

    I won't claim that I was perfect with the HV button usage since I'm still learning but for the last segment of the drive I paid a lot of attention to the state of the HV indicator and the EV range. EV range was definitely being used while in HV mode.

    Are there any other requirements to achieve this? My process was Eco mode from turning on the car until I got on the highway and was turning on cruise control. Then I clicked HV and made sure the indicator turned on. I did not turn off Eco mode, turn on sport mode, or turn on HV charge mode. AC was on and traffic caused some speeding up and slowing down that cruise control handled well enough.
  11. Clarity_Newbie

    Clarity_Newbie Active Member


    It appears to me this is one of those things that one Clarity will exhibit more strongly than another.

    In my case, once I go into HV mode, the EV range fluctuates with a slight bias downward. For example, on a 200 mile drive, if I put it into HV mode with 45 EV miles on the display...at the end of the day it may be in the high 30's to low 40's. Depends somewhat on the variables for that day.

    I attribute this to the regen which occurs even while in HV mode...HV mode uses some EV kW...the generator/motor puts some of it back plus regenerative braking if any.

    Perhaps some others who experience the situation similar to yours will chime in.

    Hope this helps.
    Last edited: Jun 24, 2019
  12. LegoZ

    LegoZ Active Member

    I also use HV Charge mode to store up motive power and burn down gas prior to a fuel stop. The hit to MPG is real BUT I can get back 26 or so highway miles and it allows me to maximize the fuel I add at the stop. The 7 gallon tank is way up on my list of pet peeves. They should have mounted the muffler sideways at the rear most portion of the car and deleted the small storage location and the used the additional space for fuel tank and given us a 10 gallon tank.
    The Gadgeteer likes this.
  13. ClarityBill

    ClarityBill Active Member

    HV mode uses the engine to maintain the battery at the level that it started HV mode. Everytime you push the HV button, it gets a new starting point - this is normally lower than the point it started at last time. It only has the engine to bring up the charge, if you are going up a hill, it will lose charge because the engine can't keep up. If you 'reset' the HV to the lower level, it will not come back.

    Did you hear the engine going to high RPM's?
  14. qwerty607

    qwerty607 New Member

    Is the idea that HV mode maintains the level when HV is started in a manual somewhere? I'd like to read more about that since mine did not seem to be doing that.
    I could definitely tell when the engine was working harder for accelerating or slight hills but not otherwise.
  15. MajorAward

    MajorAward Active Member

    Only one long trip so far, and very pleased with the way HV mode preserved the battery. I hope to never use HV Charge mode, but glad it's there if needed.
  16. 2002

    2002 Well-Known Member

  17. LegoZ

    LegoZ Active Member

    Also keep in mind if you power off the car to fuel you will lower the set point also. It would be nice to be able to set the % you want it to maintain.
    2002 likes this.
  18. Sandroad

    Sandroad Well-Known Member Subscriber

    It depends on those 20 miles running as an EV. If you pushed it to 70+ mph and had a headwind, then yes, you'll run down the battery pretty quick.

    If you are on the highway in HV (HV icon over next to the battery "gauge"), the car will hold the charge at pretty much what you started with. It does use the battery for extra oomph for passing and hills. I've done 200 miles round trips with very little loss of charge by staying in HV the entire time.
  19. Paddy

    Paddy New Member

    Great discussion. I’ll soon have my first long trip. Will switch to HV when I get on highway. Will find out soon!

    Sent from my iPhone using Tapatalk
  20. I find HV mode hangs onto charge level pretty well, but not perfectly.

    In my Florida Trip Report we only lost 24 EV range miles in over 1,600 miles of HV driving.


    If your Clarity is dropping substantially more quickly than that, I might suspect something is wrong.
    KentuckyKen likes this.

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