Best mode for long upgrades

Discussion in 'Clarity' started by neal adkins, Oct 17, 2019.

  1. stacey burke

    stacey burke Active Member

    I have not driven where you are talking about but my drive over the Colorado passes includes from Silverthorn to the Eisenhower Tunnel a 12.5 mile climb at 6% grade. Never had any problem running at 65(speed limit) over this pass, no slow down, no high revs. Car ran great. I have made this trip at least 6 times (round way trip). Also, I go over Vail pass 7% grade but not a continuous climb all the way to the top as Eisenhower is.
    MPower likes this.
  2. Sthomasa

    Sthomasa Member

    Going to Vegas Sunday. First trip with Clarity. My 17 accord hybrid was amazing but sometime struggled on steep grades.
    Thanks for advice on hv charge, sport. I also think a touch of charge will help.
    Looking forward to grade down to Baker. Wonder what charge that will add.
  3. fotomoto

    fotomoto Active Member

    That's called mountain-mode in Chevy Volt speak.
  4. insightman

    insightman Well-Known Member

    A man (I checked your profile to be certain) after my own heart! However, earlier this month, while our new concrete driveway was curing for 11 days, I finally caved and used HV Charge when I got tired of looking at just two bars. The contractor told us we could use the driveway after 10 days but I didn't want to perform the 2-ton test before it was really, really ready.
  5. Similar experience here, as well. We drove up the Siskiyou pass, followed by all the ups and downs in N Cal, then finished the day going up and over the notorious Grapevine, using HV.

    No issues maintaining speed. No significant loss of EV range going uphill. Any loss was quickly restored by HV mode once the grade leveled off. Switching to EV on long downhills can add to EV range. I’ve seen EV range increase by 7 miles on a 4 mile downhill run.
  6. David Towle

    David Towle Active Member

    Incorrect. See the thread Using HV Charge. HV Charge works great and you can use it pretty much any way you want with no significant negative effect on gas mileage, unless you are using it constantly (IOW alternating HV Charge with EV) so that the car is prevented from ever going into Gear mode. Even then the mileage loss was relatively small.
  7. Sthomasa

    Sthomasa Member

    Off for Vegas tomorrow. These trips are why Clarity beat Tesla. Did not want to spend time in Barstow.
    My plan, fill all, hv mode. Major hills, maybe Sport too? If ev dies, go to HV charge.
    Charge big time on the down hills. Hope to have half ev charge at strip.
  8. HagerHedgie

    HagerHedgie Member

    did you ever notice after cycling back to hv the first time the car tries harder to stay in gear mode? Not necessarily for long duration climbs but more for the rolling hills.
  9. Probably too late. Use EV to get to the freeway then use HV, which will maintain the current battery level. You could switch back to EV on downhill portions and regenerate a few miles.

    I may be wise to roll into town with EV range near zero. The car will auto-self-charge for free in less than 3 hours if parked within a half mile of the Strip.
  10. Sthomasa

    Sthomasa Member

    Left for vegas, 280 miles. Full everything. Showed 340 range...40 ev and 300 ice. Used straight hv and made only 240 before fuel light came on. 20 left on both hv and ev range.
  11. KentuckyKen

    KentuckyKen Well-Known Member

    You don’t have to switch to EV to get regen. HV automatically shuts down the ICE and regens on downhills. Haven’t used HV Charge yet. Does it shut down and regen on downhills or does it stay on all the time until it hits the max allowed SOC?
    MPower likes this.
  12. KClark

    KClark Active Member

    Yes this was my exact experience driving from north Glendale to Las Vegas. Three adults and luggage, 75-80mph most of the way. I had to get gas at state line, about 240 miles, because I wasn’t sure if I could get all the way to Vegas.
  13. The Gadgeteer

    The Gadgeteer Active Member

    It shuts down the ICE if the recharge from the ICE and regen exceeds some threshold charge rate
  14. HagerHedgie

    HagerHedgie Member

    My experience has been the ice doesn’t cycle off in charge mode until you reach 58% SOC. Then it reverts to normal HV mode

    Sent from my iPhone using Inside EVs
  15. ClarityBill

    ClarityBill Active Member

    Yes, My experience is also that it locks into gear mode more strongly. The ICE does not stop and start as much.
  16. David Towle

    David Towle Active Member

    Yes it does shut it off but not as quickly as in HV mode. Probably because I would think its impossible for the batteries to accept charge from 2 different sources simultaneously (here regen and the ICE) since they would not be synchronized? So for the short time when the engine is running during regen it has to be in an idle/no charge mode. Similarly I would think if you were stopped in HV Charge with the engine going and plugged it in it would either stop the engine or not permit the charge (but I'm not gonna try it).
  17. My understanding and experience, thus far, with HV it that once activated, it attempts to “maintain” the current SOC in the batteries. My observations have shown that description to be spot on.

    If I activate HV with 12 miles of EV range, the EV range will drop during acceleration or while pulling uphill. Once on level terrain or going downhill it will come back up close to the original 12 miles. I have yet to see it exceed the original EV range by a significant amount while in HV. I have seen EV range increase significantly while going downhill in EV.

    The dash display shows that the car cycles back and forth to EV while in HV, but ultimately the car is still in HV, it is just operating off the batteries temporarily.

    My impression of HV mode is similar to breathing. The batteries inhale energy when available and exhale energy when needed, while overall attempting to maintain a steady SOC. YMMV.
    TomL likes this.
  18. insightman

    insightman Well-Known Member

    When HV is selected, the Clarity PHEV's smarter-than-me brain can select any of the car's 3 underlying drive modes--EV Drive mode, Hybrid Drive mode, and Engine Drive mode--as appropriate to maximize efficiency while attempting to maintain the battery's SOC at the same level as when HV was selected.
    Last edited: Oct 21, 2019
  19. HagerHedgie

    HagerHedgie Member

    I just noticed that the other day after 26k miles. I wonder if it’s by design or a glitch.

    Sent from my iPhone using Inside EVs
  20. ClarityBill

    ClarityBill Active Member

    I think it is a fortunate glitch. It seems the HV reset does a reset on the gear mode SOC set point, but it does not reset the ICE start-stop setpoint.

    When you engage HV charge I find that the ICE will not shut off, even on long downhill runs. The ICE will go into low idle, but it does not shut off. When SOC gets to 61% it will go to HV mode (and shows charge limit message), and cannot go back to HV charge until SOC drops to 58%. This 'induced' HV mode seems just like manually selected HV mode (ICE start/stop, gear mode in/out, etc.)

    I recently had my OBDII data show 0% SOC. The engine ran around 5440 RPM, but it maintained 76 MPH going up a pretty good incline. (EV range shows 0 miles remaining at 11% SOC). It runs like HV charge until it gets up to 9% SOC, then acts like HV mode.

    In general, I am not that impressed with the Honda programming, but it is what we have. I find it best to just make it work the best that I can.

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