Clarity Plug-In Hybrid Underpowered for Touring Driving?

Discussion in 'Clarity' started by EVNovice, Jul 16, 2018.

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  1. EVNovice

    EVNovice New Member

    We live in a fairly small town on Vancouver Island, in B.C. We are seriously considering the Clarity Touring because of its roomy and upscale interior, the generally quiet ride, and because we think we could do almost all of our local driving (which is most of our driving in a year) on the battery alone (gas is very expensive here [~$1.50/L]). However, in the warm weather months we would like to do some long-distance touring through western Canada and the northwestern U.S. We are concerned that this car might be seriously underpowered when the battery is depleted, due to its high weight, especially in the mountains. Have any Clarity owners used your car in similar circumstances? Your comments would be greatly appreciated!
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  3. jdonalds

    jdonalds Well-Known Member

    Consider that the car never drives on the gas engine alone it always is being assisted by the electric motor the car has quite a bit of horsepower and you don't lose that.

    You can also charge the car while you're driving. Put it in HV charge mode.
    Last edited: Jul 16, 2018
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  4. Timothy

    Timothy Active Member

    We took it on an 800 mile round trip which we had done many times before. The Clarity was the nicest ride. It never felt under-powered. I liked HV mode and sport for a long trip on the highway.
    DaleL likes this.
  5. EVNovice

    EVNovice New Member

    Thanks for your reply. I am new at this. Perhaps a bit of instruction as to what "HV Mode" does when the battery is depleted, and then what "HV Charge Mode" does? Sorry if I am asking questions which have already been addressed elsewhere in another thread.
  6. EVNovice

    EVNovice New Member

    Thanks for the reply. What would you consider the advantage of "Sport mode" rather than "HV Mode"? I am still trying to get all of this straight.
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  8. On any trips longer than the electric range, put the car in HV mode when above 45 mph and save the electrons. You will still get over 40mpg and power will not be an issue. Try not to completely deplete the battery, save it by using the HV mode. When you get to within remaining EV range of a recharge, then go ahead and switch to EV mode and use up the remaining charge before recharging.
  9. SkipperT

    SkipperT Member

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  10. Timothy

    Timothy Active Member

  11. EVNovice

    EVNovice New Member

    Thanks! That brings up a question I had about adaptive cruise control. I saw a professional review where they said that was "brake-happy" (I guess they felt like either it tended to brake too often or too intensely, or perhaps both). Can you turn off the "adaptive" part so that it is just ordinary cruise control (i.e. no automatic braking)?
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  13. jdonalds

    jdonalds Well-Known Member

    EV: If you have ECON on with Sport and HV off you're pretty much in EV mode. The battery supplies power to the electric motor. The gas engine is normally off.

    HV: The car behaves like a Prius Hybrid in that the car alternates between electric (EV) mode (gas engine off) and having the gas engine run much of the time. The gas engine is running a generator which supplies power to the electric motor to drive the car. The generator also is keeping the battery charged at the level it was at when you switched to HV mode. Presumably in HV mode the battery will lose power until it gets down to 58% charged, and will stay there if conditions are right. While in HV mode, if you are going fast enough, the gas engine (along with it's other duties) can also be directly connected to the drive chain and will help propel the car.

    HV Charge: In this mode the gas engine is running the generator to charge the battery, up to a max of 58%, and supplying power to the electric motor to drive the car. Presumably the car is not going into EV mode at all. When the battery reaches 58% this mode will turn off automatically.

    Sport Mode: Sport mode changes the characteristics of the accelerator pedal. For the same amount of foot movement on the accelerator pedal as when in EV mode Sport Mode will cause greater acceleration. This mode also moves the point at which the gas engine will kick in to provide extra power.

    Normal Mode: The fifth mode is when Econ, Sport, and HV are all switched off. It is a mode similar to HV mode because it toggles between EV and the gas engine. But it will bias toward keeping the car in EV mode more of the time which will drain the battery until there are just two bars remaining.

    Even though you have pretty good control over these modes the car still makes decisions that may sometimes alter the behavior. For example I've watched the car when driving on the freeway at 75 mph in HV Charge mode. Normally the car will not enter EV mode when in HV Charge but in fact I've seen it do exactly that when going downhill. In that case the car enters regen mode, the wheels are supplying power to charge the battery, and the car went into EV mode.
    Last edited: Jul 16, 2018
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  14. Alex0913

    Alex0913 Member

    What a great summary!
  15. jdonalds

    jdonalds Well-Known Member

    Yes. Page 113 of the owner's manual.

    To Switch ACC with LSF to Cruise Control

    Press and hold the (interval) button for one
    second. Cruise Mode Selected appears on
    the driver information interface for two
    seconds, and then the mode switches to

    To switch back to ACC with LSF, press and
    hold the button again for one second. ACC
    Mode Selected appears on the driver
    information interface for two seconds.

    However note that when in cruise only mode the lane keep assist is also turned off.

    I find that on the freeway the ACC works pretty well. It is a bit slow to accelerate automatically when coming out from behind a slower vehicle. Also I've learned that if I'm changing lanes, into a lane where there is a car that will then be in front of me the car will break if I'm too close to that car. But other than a few definable conditions it works pretty well.

    On the other hand when I've used ACC on roads that have a lot of turns it may not work so well. The ACC can easily lose radar sight of the car in front of my if the curve in the road is tight. Also if the car in front of me slows somewhat to turn off to another road the ACC will often brake.

    Another condition is on a curvy road the ACC can sometimes think a car coming in the opposite direction is a hazard and will apply the brakes. Sometimes the car momentarily brakes too hard. Applying the accelerator eliminates the immediate problem.
  16. DaleL

    DaleL Active Member

    On a long trip, I recommend keeping about a 50% battery charge in reserve. Drive Until the tiny 7 gallon gasoline tank is almost empty (20 to 30 miles past the low fuel warning) and if needed use the electricity to get to a gasoline station. I took a 2000+ mile trip from Florida to Ohio and back. My Clarity was just fine in the mountains.
    neal adkins likes this.
  17. Tailwind

    Tailwind Active Member


    The basic premise of your original question is faulty. The battery is never fully depleted. If you do nothing at all with the three mode select switches on the center console, you will start out a drive in EV (electric vehicle) mode. In this mode, the car uses only the battery to drive the vehicle forward. If you need to accelerate quickly or otherwise need more power than the electric motor can provide, the car will automatically go into HV (hybrid vehicle) mode. It will start the engine and supplement the electric motor giving you the power you need to either merge into traffic or climb a hill. In this case, the engine will continue to run for a short period after the power requirement drops below that required for EV mode only. This is to allow the engine to come up to operating temperature and ensure a smooth running engine.

    Once the battery gets down to approximately 10-15% of capacity, indicated by two bars of charge on the battery level indicator on the left side of the instrument cluster, the car will switch to HV mode all on its own. Now the motive power of the vehicle will be supplied by the engine driving the generator and that electricity powering the traction motors. In this mode, if the electricity provided by the generator is less than that required to move the car, the excess will be used to maintain the battery at the 10-15% charge level. If the power requirements exceed the capacity of the generator, then the battery will supplement the engine generated electricity giving you more than adequate performance. The car will seamlessly switch from HV mode with only the engine providing power to HV mode with the engine and the battery providing power to EV mode where only the battery is providing power, to, at times, EV mode with the car going into regenerative mode to charge the battery. Additionally, when at highway speed, the engine might directly engage the wheels and drive the vehicle forward mechanically.

    The whole point here is that the battery is never depleted. When the battery gets down to the 10-15% level, the car becomes just like any other hybrid, using electricity from the engine driven generator, the generator and the battery, or just the battery depending on the need.

    Where you to drive your car cross country without the benefit of being charged to full battery capacity, you will get approximately 450km of range from gasoline only, depending on driving conditions and your driving habits. That should be a practical drive time of between 3 and 4 hours. While this is shorter than a lot of vehicles, it is still sufficient to get you to your destination without having to stop too often.

    It is certainly possible to use the mode select switches to force the vehicle into HV mode, or to use HV charge mode to charge the battery up to the 58% level, but it isn't necessary. You can just drive the car like any other and have the benefit of not using any gas for your local trips, and going on longer trips using gasoline just like any other hybrid.
    AnthonyW and bfd like this.
  18. KentuckyKen

    KentuckyKen Well-Known Member

    I agree with Tailwind but with one caveat. If you know you’re heading into the mountains or have several long steep hill climbs ahead, it’s best to select HV before the battery is depleted to 2 bars, O EV range, and auto switch over to HV. This way there is plenty of charge “in the bank” and the algorithm has more freedom to choose among the various power flows to achieve the best performance, economy, and prevention of the high reving angry bees noise.

    I just did a 500 mile round trip with some significant hill climbs and starting out in HV with a fully charged battery I experienced absolutely no loss in power and never heard the angry bees. On the longest steepest hill, the engine only reved to a low hum. And I got 48 mpg and only lost 1 bar of charge so I had plenty of charge left for local driving at the end.
    I don’t think you will have any problems touring in the Clarity at normal altitudes.
    PHEV Newbie likes this.
  19. JCEV

    JCEV Active Member

    And electric motors are not affected by altitude in terms of power so that is a benefit although you will see worse mileage in HV mode at higher altitudes since the motor has to work harder to power the electric motor.
  20. EVNovice

    EVNovice New Member

    Thanks all for the very informative responses! I appreciate your collective wisdom very much.
    I have one follow-up question:
    I am trying to get a rough idea of the cost of a "typical" battery recharge (i.e. how many kWh it would take times my local electric rate charge). Would I be correct to assume that one would typically draw the battery down to 10% to 15% of its starting charge (call it 12.5% for simplicity), and then the car in HV mode would maintain this. So when you get home to recharge, since it is a 17kWh battery, would it then take (0.875 X 17kWh) of electricity from the home charger to revive it? Or is there some inefficiency from the charging operation so that it actually takes more than this to revive the charge? Thanks again for your help!
  21. JCEV

    JCEV Active Member

    It's usually around 14 to 15kwh full charge in 12ish hours. You're about right. I would charge every night to top it up. Which would be about 50% most nights so 6 to 7 hrs will top me up . Ive only had it one day and in 8 hrs I got 60% from a level 1 charger had 0 EV range left.
  22. JCEV

    JCEV Active Member

    Btw this car is definitely not underpowered I was really surprised , you can blow away from a red light easily in EV. Most drivers are very slow .
  23. A charge from empty takes about 14KWHs, as it does not use the entire rated 17KWHs, it holds some back. If you multiply the cost per KWH x 14, that is the cost of a full charge. Here in the Seattle area, PSE charges about 10 cents per KWH (actually 9 cents for the first 800 then 11 cents after that), so about $1.40 per charge, the cost of a little over a third of a gallon of gas. At this rate, if you can go a little more than 50 miles on a full charge, then about 150 miles for the cost of a gallon of gas. These are round numbers and some areas seem to charge a lot more than 10 cents per KWH. 30 cents per kwh would be about the equivalent of 50 miles for the current price of a gallon of gas. Hopefully my math is not defective.

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