Regenerative Braking

Discussion in 'Hyundai Kona Electric' started by Boston Charger, Jun 16, 2019.

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  1. TheLight75

    TheLight75 Active Member

    Around these parts, slowing as you approach a red light could definitely cause a fender-bender as most drivers are extremely impatient and will ride your tail since you aren't minimizing the gap in front of you. This happens ALL the time to me on the highway when using ACC @ 75mph and drivers behind me see a decent gap in front of me; sometimes I cannot see the headlights of the vehicle following me because they are literally 1-2 feet off my bumper.
     
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  3. NeilBlanchard

    NeilBlanchard Active Member

    My brother has the original 1-pedal EV, which is the i3, and it has a good "detent" which is easy to find, and you can feel the car coast. And the Bolt EV when it is in B also has 1-pedal driving. I fully understand how to feather the accelerator pedal, and I am good at it. But, no matter how good you think you are, you cannot keep from getting a little regen and a little power. And when you do, that keeps the vehicle from just coasting.

    Believe it or not, coasting can often move the car faster than if you were feathering. Lift and coast means no effort, and you don't have to watch a gauge - when you should be watching the road. It means actual free wheel coasting, and this means that you spend less time accelerating. It means no unintended slowing - which you then have to make up for.

    MOST of the time, we are driving forward, and only a small fraction of the time do we need to slow down. Regen on the brake pedal, or when you shift into another mode, or using the paddle (which the Bolt EV also has) - and you get all the regen you need.

    But not when you don't need or want it.
     
  4. NeilBlanchard: To demonstrate what you are claiming, please show us the avg kWhs per 100kms, or miles per kWh (not sure what country you're in). Use your car computer dash display to show us a pic of that number. And how many kms in that avg? The last 1000 kms would be good as it would exclude the winter driving. Also what is the normal avg of other drivers with your car make (or manufacturer's spec)?
     
  5. 5.3 mi/kWh does not sound that good for your type of driving. Our Kona is spec'ed at 258 mi range with a 64 kWh battery. So that makes it about 4 mi/kWh. I know I have been exceeding the GOM range number with city driving, so would be even better. I would not be surprised to hit 5 with my city driving, with no effort to hypermile. But in fairness, I have not had my car long enough to log and confirm any longer term efficiency numbers.
     
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  7. XtsKonaTrooper

    XtsKonaTrooper Well-Known Member

    Bjorn hypermiled at these avg speeds or approx 44kmh.
    His full charge was in the 800km range.
    I cant remember what that worked out to kwh per 100km but im sure someone else remembers that number.
    Neways, these numbers are irrelevant to me because i never drive at average speeds of 25mph.
     
    Last edited: Jun 19, 2019
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  8. NeilBlanchard

    NeilBlanchard Active Member

    That is only the first picture, and it was over 1600 miles, with 3 different drivers. It was 103 miles farther than the EPA range of 238. That's a 42% improvement.

    And at the moment, we averaging up to 5.9 miles / kWh in our Bolt EV.

    The 2014 Leaf S had a 24kWh pack, and the 2015 e-Golf SEL had a 24.2kWh pack.
     
  9. That would be 7.75 mi per kWhr, which is a lot more than NeilBlanchard is achieving with his coasting.
     
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  10. NeilBlanchard

    NeilBlanchard Active Member

    He was using a lot of coasting to do this. And he was just driving to hit the maximum, and driving very slowly - my family and I are doing ordinary daily driving.
     
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  12. Kai Richardson

    Kai Richardson New Member

    New Kona EV Ultimate Owner in Maryland. 2000 miles so far.

    This is what I take from this thread so far, and from Googling about regenerative braking vs. coasting generally: All things being equal, in a perfectly controlled environment, with the same car, same driver, same driving conditions, etc. etc., then max coasting will result in the highest EV range efficiency.

    However, are things really all that equal? Most people are not hyper-milers, itching to extract every mile out of a single charge. Most people will drive in a mix of environments, both in terms of "flat" vs. "hilly" driving, and in terms of climate. And of course, we are driving different cars from different manufacturers with different approaches to implementation of regenerative driving. Even Mr. Blanchard alluded to the fact that different circumstances require different approaches.

    It would be helpful if we could go back to the original question which focused on regenerative braking for the Kona EV, rather than a theoretical discussion on EV regen mechanics in general. For example, in the Kona EV you have four levels of regen, and you have three drive modes (eco, normal, sport). There is a display that shows expected "eco" benefits for each drive mode/regen combination. You have the ability to change the regen rate (overriding the default) for each drive mode. If coasting was always more beneficial, you would expect the "eco" benefit (which I assume translates to kwh efficiency) to go up when reducing regen rate for a given mode. However, the display shows the exact opposite! The "eco" benefit increases as you increase regen rate for any given drive mode.

    For example, in "Eco" mode, with max regen set to max (3), the display says "85% eco benefit". (Or something like that, it is not right in front of me as I write this.). In the same mode, if you reduce regen to 2, then the eco benefit display changes to "65%" (Again, not exact, but you get the idea.)

    So, either the display is complete BS, or the definitions of "eco benefit" is not clear, or Hyundai has implemented a system where the efficiency of regen is always better than coasting because of the particular way Hyundai has engineered the Kona. Quite frankly, it is not clear what the real difference is between the drive modes, other than climate limits, speed limits, and regen rate. If you set drive mode to "Eco", with the same settings as "Sport", is something else happening that is not in your control that is creating a difference between these two modes? Who knows, it is not clear.

    In the end we average Kona owners just want to know this: in average, every day, normal driving, is there any real benefit to regenerative braking at all in the Kona EV, other than personal preference?
     
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  13. I am sure he was doing more than just coasting with his hypermiling, probably very easy on the acceleration, too.

    I do know that driving in the city, despite all the stop and go and with no "coasting", I get much better range than on the hwy. But what I don't do is make myself a traffic hazard by interrupting the normal flow of traffic. So I will probably never achieve anywhere near 7.75mi/kWh. I would not be surprised to hit 5 though (without coasting), and one day will get around to tracking that.
     
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  14. OK, just went out to my car and took a pic of my current driving stats for today so far. All stop and go city driving, no coasting, and no babying the throttle either. In fact, I am a bit of an aggressive driver, in that I like to be the first off the line at a red light. As you can see, it shows 12.0 kWh/100 kms. That equates to 5.2 mi/kWh. Better than I expected, actually, and pretty well the same as NeilBlanchard with his "coasting". I guarantee you, though, I would never be accused of being a hypermiling doddler!! DSC_0462 (800x444).jpg
     
  15. Well, it depends on traffic. Here in Vegas you would be honked at all the time. I get more than 7-8m/kwh on the way to work only because it's a slight decline. But on the way back I get about 5. And I'm driving "normal" too. I use Regen 2 with auto Regen and I accelerate pretty normal. I'm in Eco mode and try to not get into the red to much.

    So there is no magic to it! And honestly, I just enjoy driving my EV and I don't need/want to hypermile it on a daily basis. I enjoy pushing the pedal when I want/need to.

    Sent from my moto x4 using Tapatalk
     
  16. NeilBlanchard

    NeilBlanchard Active Member

    Keep an eye on it, and see how you do over time, in all weather conditions, and at a variety of speeds, and changing elevations.
     
  17. Stickyman

    Stickyman New Member

    Only owned it for two weeks and have left it in auto Regen for most of it. I like the set it and forget it. I will use the paddle to stop on my street commute. On the highway I will let the ACC take control.

    On the flip side I have heard that this car will coast forever if you turn off Regen. I will try it next time I have open road.
     
  18. I've had my Kona EV for just a little over a month now and have been driving mostly in normal mode on regen 3 since I discovered the regen mode about a week after I started driving it. My commute (which is 95% of the mileage I put on the car) is 17.5 miles each way on surface streets with speed limits ranging from 25 mph to 50 mph. I just really enjoy how responsive the car is to the throttle both accelerating and decelerating in this mode. It reminds me of driving slot cars when I was a kid. I did not even know about auto regen until reading this thread earlier today, and plan to try it out on the way home today.

    I'm not all that worried about hypermiling, as I was with my Fusion Energi, which I traded in for the Kona when its lease was up. My EV range in that car went from about 25 miles to about 18 miles during the three years that I owned it. I tried to squeeze every electric mile out of it that I could during my daily commute to avoid the gas engine coming on. I started out being able to drive all the way to work and sometimes 2/3 of the way home on a charge, but ended up barely making it to the office in the morning. Now, I have a range of over 300 miles so... no problem.

    I've been averaging about 5.3 mi/kWh without worrying about squeezing every last mile out of a charge. I'm honestly more interested in my pet project of following my home electric use and the interaction of EV charging, solar PV and Sonnen storage battery, with the new SDG&E PV rate. I actually accumulated a $35.00 credit in the past month even though my net usage was about 125 kWh, due to charging at low rates, and solar production in the afternoon at much higher rates. Of course May and June are pretty mild months here in SoCal, so we will have to see how it all works later in the summer when the AC comes on in the afternoon.
     
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  19. TheLight75

    TheLight75 Active Member

    In ECO mode, I typically get 5.6 mi/kWh in street traffic, about 4.3 mi/kWh on the highway with regen set to 2. The Kona has a very nice range profile! My last full charge GoM was at 318
     
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  20. My Kona EV Limited doesn't have the auto regen function available, that I can find. Is it included only at the Ultimate level?
     
  21. XtsKonaTrooper

    XtsKonaTrooper Well-Known Member

    ^^^^^^^^
    Is it enabled, in the settings.
     
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  22. I went to settings, to "convenience" I think, where it should be according to a youtube video that I watched (apparently made in UK) and could not find it there. I scrolled through all of the settings menu and could not find it. Maybe I missed something. I live in California - perhaps it's not available in the US or something?
     

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