HV Mode Question

Discussion in 'Clarity' started by dubu_x, Sep 20, 2018.

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  1. dubu_x

    dubu_x New Member

    Hey guys,

    My apologies if this question has been asked and answered before. Recently, I've been switching to HV mode while going up a hill (about 2 miles long). I've noticed that at the bottom to middle of the hill, my car feels like I'm driving in EV mode but when I'm almost to the top of the hill, my car gets really loud (I'm assuming this is the angry bees that were mentioned). The angry bees don't really bother me, but it's the way the car feels. I don't really know how to describe it, but it feels like the car isn't as responsive? When I am in EV mode, the car feels heavier, but when I'm near the top of the hill, it seems like I have to apply a heavy foot on the accelerator and even with the pedal pressed down, my car is struggling to move.

    This problem isn't just related to going up hills. Whenever I use up all my EV range and ICE switches on, I have the same issue. I can hear the engine really loudly but I have to step on the accelerator pedal quite firmly in order for my car to move.

    Is this normal?
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  3. stanigu

    stanigu Member

    When the battery depletes, the ICE has to do all the work and the electric motor is not contributing much to the propulsion, so the sluggish response is normal. I learned early on that you never want to deplete the battery completely (i.e. 2 bars) if you can help it. I engage the HV mode on the highway to maintain the charge, so once I get off the highway there's plenty of battery juice left and the car is responsive.

    I can't speak for the hill climb issue--I'm not sure why it would rely more on ICE as the vehicle climbs (unless you already had low charge at the bottom of the hill and you had no charge left towards the top).
    KentuckyKen likes this.
  4. neal adkins

    neal adkins Active Member

    I had the same issue when climbing a long uphill grade of about 15 miles. So now, as previously mentioned, I make sure to have enough battery to avoid the sluggish response. I usually use hv charge mode, if nessacary, to replenish the battery well before I need it to climb. Instead of hv mode I favour sport mode while climbing because Hv mode will strive to maintain the current battery state and will still cause the ice to rev high when climbing for several miles, even when you have some battery remaining. Hv mode may work ok if it's only about 2 miles.
  5. neal adkins

    neal adkins Active Member

  6. DaleL

    DaleL Active Member

    "Whenever I use up all my EV range and ICE switches on, I have the same issue. I can hear the engine really loudly but I have to step on the accelerator pedal quite firmly in order for my car to move."

    There seems to be quite a variance in how noisy the Clarity engine is. When I go to the HV mode for interstate driving, heavy acceleration, or the battery is depleted, I cannot even hear my engine except at very low speeds. The only exception is between 45 and 70 mph and very heavy acceleration when the engine directly couples to the drive train. Even when the Clarity's battery is depleted, it should retain some power (2 bars) in reserve.

    However, the engine in the Clarity is only 103 hp max. That is not much for a 2 ton car. If the battery is really fully depleted, such as during a long uphill climb, the car would certainly be sluggish as it would only have the 103 hp ICE for power. I live in Florida where there are no such hills. However, I did take a 2,000 mile trip to Ohio and back last June. I kept the battery charge at about 1/2 way. I did it because of the tiny 7 gallon gasoline tank and a bit of range anxiety. That also served to insure there was plenty of battery power available for the mountains along the trip. I did not encounter any sluggishness or noticeable engine noise.

    On the basis of my experience with my Clarity Touring, I don't think what you described is normal.
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  8. Sandroad

    Sandroad Well-Known Member

    What you describe----heavier feeling behavior when the battery is depleted (EV range used up)----is perfectly normal for the Clarity. As mentioned in previous posts, the ICE can move the car ok without battery power, but it's just adequate. And, you'll really feel that going up hill. It will take some practice to balance use of the modes to get the best driving experience for your situation, but for sure keep your battery charged up enough to last to the top of the hill by switching into HV mode earlier.
  9. stanigu

    stanigu Member

    I actually climbed some pretty steep hills in San Francisco tonight (yes, the City has a few). I had EV mode engaged, with about 70% charge left. But towards the top of some hills, ICE kicked in...I think the car needed more power. As soon as I was past the hill, ICE stopped. So that might be what's happening.
  10. weave

    weave Active Member

    I live in a mountain area, I don't use HV mode at all when climbing mountains. I make sure I have enough battery so I can run up a mountain with just EV on only. It always does very well. If I have to I'll run in charge mode on a flat road at highway speeds to ensure I have enough BEFORE I get to the mountain.

    Also of course when going up, the range drops really quick so that has to be planned for as well (although you get a lot of it back going down on the other side)
  11. PHEV Newbie

    PHEV Newbie Well-Known Member

    I mentioned this on another thread but HV does really well when going up grades when you have a full to nearly full battery (greater than 60%). With that, it combines electric generation from the ICE combined with a bit of power from the battery (you can see this with the energy flow screen). The ICE hums pleasingly and you have plenty of power to go up the grade for miles. Once your battery goes below a certain level (50-60%), the ICE gets louder even though you might have plenty of juice from the battery to get you up the hill. The Clarity doesn't know if the top is in one mile or thirty so it seems to want to conserve battery power should you need it. As others have mentioned, if it relies only on the ICE to generate electricity, it's gonna be pretty slow even though the engine is racing. It this happens and you know the top is a couple of miles away, just switch out of HV mode for the extra power. This is yet another reason to keep as much charge on your battery as possible on a road trip.
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