Let's talk about your Fall/Winter EV range drop

Discussion in 'Clarity' started by Rav, Dec 17, 2019.

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  1. KentuckyKen

    KentuckyKen Well-Known Member

    @Dan Albrich , I would suggest letting the algorithm decide whether or not to use ac when defrosting/defogging the window. I base this unproven hypothesis on the observation that ac is much, much less draining than resistance heating. So if its use lets you turn off or turn down the fan and heat sooner, it would be a net energy gain. Might be worth a try, but the savings are probably too small to easily quantify. If nothing else (if true), it lets you just use the climate control without having to input manual settings without guilt.
     
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  3. Dan Albrich

    Dan Albrich Well-Known Member

    Thanks Ken. I tend to agree. I don't see a big difference by manually selecting defrost+feet, and then pressing AC off, vs. just pressing front.
    I'm delighted with this car. I admit that if my required range was longer that I'd be burning gas, but it turns out I average about 30 mi per day which is about the same I often get in winter driving. And if I do burn gas, I don't burn a lot.

    Also I forgot to mention I absolutely do use scheduled climate control daily (and have level 2 charger). I think that also helps a bunch. I think you and others in this forum helped me with that decision (to install level 2).

    Hope you and others in this forum have a Merry Christmas (and/or excellent holidays as you prefer).
     
  4. MrFixit

    MrFixit Well-Known Member

    Dan - This is an interesting point.
    In theory, if you end up at the same altitude where you started, you should not be greatly penalized by the 'hill'. This, because regeneration should recover what is lost going up when you go down by equal amount. This works better if you live at the bottom of the hill and commute uphill regularly. In your case however, if you start with a full charge and immediately go down, there is no place for the downhill energy to go (because the battery is full) and you truly waste the potential energy of the hill.

    You would like to be able to start with a SOC less than 100% such that your downhill run charges you up to 100% just as you reach the valley. That way you aren't 'wasting' potential energy. The Clarity probably won't do this very well because it will never regenerate completely back to a full charge.

    Recently, @Walt R did this simple potential energy calculation:
    "OK, geek time: a 4200 lb car will gain about 1 kWh of energy by being raised 650 vertical feet. Which means, assuming around 4 mi/kWh, that it will lose 1 mile of range for each 150-200 vertical feet. So at a 3-4% grade, for each mile of horizontal distance, you will also lose another mile of range from elevation, costing 2 miles for each one forward. At 6-8% it will be 3 miles for each one forward."

    For your scenario, losing the potential energy of the 'hill' would cost you 1.54 kWh, or roughly 6 miles of range. For example, your first trip of the day could waste this much... But -- If you did a subsequent trip (without charging in-between), you would not waste nearly as much.

    Here is a fascinating real-life application that takes amazing advantage of a hill, creating something that is 'resembles' perpetual motion:
    https://www.greencarreports.com/news/1124478_world-s-largest-ev-never-has-to-be-recharged
    It is a perfect example of an actual application with 'excess' regeneration. In this case, the home base is at the bottom and the trips are up-hill (the opposite of your case), but this was ingenious !
     
    Last edited: Dec 18, 2019
  5. So to replicate this, you first need to load your Clarity with a payload equal to 144% of its curb weight each day, depart with a low state of charge and then dump the payload when you reach the valley :).
    Of course, the dump truck probably benefits from a higher regeneration efficiency than the Clarity as a result of economies of scale.
     
  6. MrFixit

    MrFixit Well-Known Member

    I think you're onto something here !!!
    Let's see... payload of 144% of curb weight would require about 38 people. Just load 40 people in.
    Drop them off when you reach the valley (they can walk back up so they are ready for the next day's run).
    Maybe you will have to pay them to provide this service for you, but money is no object -- you are saving the environment !
     
    Last edited: Dec 18, 2019
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  8. KentuckyKen

    KentuckyKen Well-Known Member

    Or...
    Just convert your Clarity to unlimited, clean fusion power by installing enough solar PV to power your house and car. Might even be cheaper than hiring and feeding those 10 human potential energy weights.
    PS: You guys and gals are great! I never cease to be amazed by the ingenuity and humor on this forum.
     
  9. jdonalds

    jdonalds Well-Known Member

    We have a 1/2 mile long 14% downgrade one mile from our house. Driving that mile apparently uses just enough power so the downhill regen doesn't have to kick the ICE on. At the bottom of the hill we usually have EV range that is identical to the EV Range indicated when we pulled out of the garage.

    The rest of the trip to church is an average slight downhill. Church is 7 miles from home but the EV Range shows we've only used about 4 miles of the estimate. The return trip then is almost all uphill. By the time we've returned home and pull into the garage the car shows we've traveled 14 miles round trip, and used 14 miles of EV range. The estimate is spot on in spite of the hills and 500 foot elevation change.

    Of course if we vary our driving pattern, accelerating more or less away from traffic signals and stop signs, or going faster or slower on the route, we can effect the power used. But we've made that trip so many times in the Clarity over the past two years I believe the EV Range estimate is fairly accurate.
     
  10. Dan Albrich

    Dan Albrich Well-Known Member

    Good points. Here's my experience RE hills. I think my 1000' hill, which is super-steep occurs in about 1/4 mile (if), so I literally lose about 5 miles of EV range each time I go up. When I come down, I gain about 1.2 miles of EV range. This just by what I see on the display. So for a round trip, the net loss is about 4 miles. And as noted, each morning I wake with full charge, head down the hill with no room to charge, so ICE sometimes engages. I've learned to just turn on cabin heat on way down hill (useful this time of year anyway), and that keeps ICE off, especially if I use breaks and not paddles to slow.

    But yeah, regen isn't even close to 100% recovery. I estimate it at about 20% for same hill, down/up.
     
  11. Sandroad

    Sandroad Well-Known Member

    Also as a previous PHEV owner (Fusion Energi), I fully expected a winter range drop and the Clarity is well within what I had thought would happen.

    What is usually missed in these complaints is the much greater than average range in the summer. For the year here in lower Michigan, I average 47 mpc, just what the estimate is for the Clarity. Winter is about 15 Mac lower and summer is about 15 mpc higher. I don’t precondition because I’m retired and have a spur of the moment type of schedule. Except for the morning dog walk which my OCD border collie says has to happen at exactly 8:30.

    I really like the Clarity in the winter. Fast cabin heat, good winter handling, excellent view out and no wasted gas with a cold ICE. If I were to complain about the winter Clarity, it would be about the windshield washers, not the range.
     
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  13. Dan Albrich

    Dan Albrich Well-Known Member

    So a couple thoughts to ponder. One, I really hate that so many products of all types over-promise and under-deliver. Why not flip that, give a conservative estimate, and have folks be delighted when they can exceed the estimate?

    How many threads on this forum alone start with a new owner shocked by decrease in EV range as winter comes on? If it's obvious that EV's do this, it certainly isn't what I'd call common knowledge. Or clearly isn't known to the folks who start those threads-- and I don't blame them; it's not obvious that winter range can be 30-50% less than summer.

    Also, if you consider a purchase, you really don't want overly optimistic descriptions of the product. You want honest and inclusive evaluation. EV's by their nature perform very differently from user to user. Let's just acknowledge that. It involves temperature and heater use, hills or lack-thereof, rain (water resistance), ..., and how one drives, etc.

    I'd actually prefer (for EVs) a winter summer estimated MPC. Kind of like we see for highway/city. i.e. In my case I'd say something like 25/47 (low in winter/best in summer). 47 may be a valid average for some folks, but not even close to reality in my case. I tell friends considering the car, it gets 30 EV miles which I feel good about. They may have days with 25, and days with 43, but I'd rather under-promise and let someone be pleased when the estimate is low.

    And certainly not provide any estimate that will be 'shockingly wrong' seasonally.

    BTW- one friend who did buy Clarity after me, does not live on a hill, and sees only slightly better numbers than me. It may be that our climate in Western Oregon just requires daily defrost and heat to such a degree that we simply never see numbers other locations do. So be it, but again, we all see something different.
     
    Last edited: Dec 18, 2019
  14. Bend

    Bend New Member

    @Dan Albrich have you tried any anti fog treatment on the interior glass? I’m on the drier side of Oregon, but Rainx Antifog treatment helped keep the windows clearer during a recent rainy spell.
     
  15. Tomrl

    Tomrl Member

    Coming up on 1 year of ownership! I couldn't be happier, not a single anomaly to report. I've been getting 39 miles at my charge up this winter, have gotten up to 60 in summer before heading out on a couple trips that were pretty much completely HV. I'm not anal nor am I really that careless about E usage, just run all heat systems as required for a comfortable ride.
     
  16. bfd

    bfd Active Member

    If this conversation was about the BEV model, the yearly winter decrease in available EV miles would be a huge concern. It's exactly why I didn't consider that version of the Clarity, even though there were some compelling lease rates. That BEV version - in conditions similar to what people are describing here - would likely mean a range estimate somewhere in the mid-60s. That limited range would make Clarity BEV ownership unfeasible for most of us.

    However, the winter range reduction is merely an annoyance for PHEV owners.

    There's good reason for a 7 gallon gas tank in the PHEV version.
     
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  17. Dan Albrich

    Dan Albrich Well-Known Member

    Just as a quick followup, yep, already using Rainx Antifog. It's a staple treatment of survival. Even so, the glass does fog, and basically every time I drive seasonally. But yep, agree, it's way worse without it. I am also sort of extreme about keeping the windows clean which does seem to help.

    One last comment, and to reiterate. I absolutely love this car. My comments which are stating limitations I experience are intended for others who do not see stellar EV range estimates. i.e. It doesn't mean you got a broken Clarity. And more specifically, in my experience the most significant factors that really matter are elevation gain (mostly 'live on hill' or 'don't live on hill') and heater use. The other stuff matters too, but these two should have a factor of 5 or something relative to every other tune-able thing. I mention this last bit because I went freaking mad trying to tune my driving style to get some 'reasonable' EV range estimates, and no matter what I tried just couldn't eek out anything significant. I much later realized living on a steep hill subtracted like 10 (or more) estimated EV range miles from my car out of the gate. And, this isn't tune-able for me.

    My table would go something like this: (some comments specific to winter)
    - I live on a steep hill. Subtract (at least) 10 EV miles range from everyone else. Don't pass go. Huge lack of bonus here.
    - I routinely run heater in any form (including defrost), and basically cannot turn it off and still see the road. Subtract another 6-10EV miles from others.
    - I do jack rabbit starts (and other inefficient driving) routinely and like to hit the pedal. Subtract a few - like 3 EV miles from others who do not.
    - I drive in rain often, with wipers running and head lights on. Subtract like 1-3 but really it's more the heater that kills you. The head lights are almost zero. The wipers are likely very low cost too. The resistance of wet road on tires is what matters.
    - I run with heated seats on. - This is a good thing. It might technically cost you a mile or two of EV range, but you more than get it back if it allows you to run cabin heater less.
    - I have level 2 charger and precondition daily. Get back a couple EV range miles from lower heater use in winter.
    - Driving on highway, including routinely, at higher speeds. Known to hurt EV range. I basically never do this so cannot comment on EV cost (small town, no highway on my commute).
     
    Last edited: Dec 28, 2019
  18. MPower

    MPower Well-Known Member

    I had a 2012 Prius Plugin before the Clarity. The EV mileage estimate did not change much year round at around 9 miles. I believe the most it ever showed in all the years I owned it was 11 miles-maybe once. What happened to keep the EV mileage up?

    In the winter here in Vermont (sub-zero temps), the ICE turned on every time I drove it out of the garage whether or not I had the heater on which I usually did not if I was only driving locally. According to the manual, the ICE would turn on any time the battery was not happy with it's temperature. It's happy place seemed to be around 50-60ish. It would almost always turn for the first trip of the day, after that it would tend to stay in EV until it ran out of juice unless I used the heater of course which ran off the ICE.

    I liked my Prius, but I am not sure it was that happy with hills and temperatures of Vermont.

    My Clarity EV estimate went down to a low of about 29 last winter. We haven't hit that low this year, because the temperatures have not gotten as low yet.
     
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