Featured Snow job about EV range in heat and cold

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by bwilson4web, Feb 9, 2019.

  1. bwilson4web

    bwilson4web i3 and Prime

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    By now, anyone with a pulse who reads/watches the news has seen a blizzard of titles touting EVs lose "40%" of range in the cold. Here is a small sampling of these news titles:
    [​IMG]
    Although technically correct, they are misquoting the report and seldom discuss all of the results. The AAA did publish a link to the report and I started a thread in the "EV" area with a link to the report and hope we can discuss the technical details:
    Heat and cold effects on EV | PriusChat

    The AAA sponsored report is a well written, quality, engineering report. Sad to say, many reporters and editors, especially the lazy, non-technical, or anti-EV crowd, are too quick to misquote. This means you'll likely find co-workers or family members who will ask you about the loss of range even if you drive a hybrid. So I wanted to offer two, quick replies before suggesting 'lets read the report.':
    • They tested five EVs, not my car. - if you drive a Prius or other pure hybrid, your car was not in this report. There is a cold and hot weather effect in the 5-9% MPG range that has been discussed in PriusChat.
    • Pre-Conditioning, the EV equivalent of warming up the car, solves the problem - without having to leave the car running. It typically costs 10 cents in 20-30 minutes to get the car ready.
    I was torn between posting the 'in depth' technical report here or in the "EV" forum. But I realized the buzz about EV weather effects would spill over onto Prius and other hybrid owners.

    There are probably even better, answers for these ad hoc questions so I thought let's chat either here or "Fred's House of Pancakes." Good Prius friend, @john1701a probably has a better list of quick replies from his decades of studying hybrid skeptics.

    Bob Wilson
     
    #1 bwilson4web, Feb 9, 2019
    Last edited: Feb 9, 2019
  2. bisco

    bisco cookie crumbler

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    i wonder if it's even possible to make a blanket statement about all ev's in general, or if different chemistries and conditioning systems affects the percentage

    i'm down about 30%, 7 year old car that is charged in an unheated attached garage. that may have some effect, idk.
     
  3. I'mJp

    I'mJp Active Member

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    Nobody talks about the cabin temperature, what it's set to, and how long.

    My car fogs up if I turn the heat off too long, so I'm forced to reduce the range.
     
  4. Usle

    Usle Member

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    Living in NH gives one a better understanding of the effect cold air has on auto travel, bearings are affected, air pressure in tires is affected, and...my prime range changes, during the summer it's 32-33 miles, today it's 21.1, one third less electric range.
    That 21.1 miles is also effected, the computer thinks it's going to go 21.1, in actuality, the cold is going to make that range less.

    Using the battery to warm the battery?

    The ability to control the temp of the liquid circulating to cool the battery would be good, getting the sucker up to 100 degrees on a 20 degree day would be helpful.
     
  5. Zythryn

    Zythryn Senior Member

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    It has little to do with battery chemistry and more to do with physics.
    Any vehicle will use more energy in winter.
    The exact amount can vary. We lost about 20% efficiency in our Prii and about 30% in our EVs.

    ICE cars have the “advantage” of having readily available heat. However, they produce more heat than you need year round.
    As a friend of mine once said, ICE cars are great heaters, that produce a bit of motive power as a side affect.
     
  6. bwilson4web

    bwilson4web i3 and Prime

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    They tested five, 2017 model EVs but it is also a dynamic technology. IMHO, a thermally insulated battery pack, perhaps with aerogel would be the next big thing.

    Bob Wilson
     
  7. hill

    hill High Fiber Member

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    Back in the 80s, the Nissan / Datsun (whatever it was called back in those days) near the Canadian / Washington / Idaho border, the car that we drove there in was so cold soaked, it wouldn't even start. I wonder why the authors of this kind of Claptrap won't write up this kind of scenario in order to set my hair on fire. After all .... those are much more frequently experienced scenarios. Oh! I know... is it because that's so ubiquitous? Like gasoline cars catching on fire? By the way, to my knowledge, despite all the model 3 vehicles running around nowadays, there have been no fires . That's truly got to gaul the opposition / haters / drama queens.

    .
     
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  8. bisco

    bisco cookie crumbler

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    it is true that gasoline engines are not as efficient in the cold either. and of course, the rest of the mechanicals in the car, as well as friction loss
     
  9. El Dobro

    El Dobro A Member

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    Seat heaters have a hard time keeping the windows clear. :p
     
  10. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    The typical gas car has enough fuel to move the car 1500 miles.
    2/3rds of that is wasted as heat all the time...except in winter when you want the heat.

    Mike
     
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  11. Salamander_King

    Salamander_King Senior Member

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    Haven't read any of report yet. But n=5 is such a small sample.
     
  12. Zythryn

    Zythryn Senior Member

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    Minor note. It would me more accurate to say 'except in winter when you want some of the heat. ;)
     
  13. bwilson4web

    bwilson4web i3 and Prime

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    True and their results showed variability.

    The current EPA tests includes cold weather metrics but there is no identifying numbers showing relative cold sensitivity or heat effects. It seems like useful information.

    Bob Wilson
     
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  14. jdcollins5

    jdcollins5 Senior Member

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    On the Model 3 forums, some of those in the northern US and Canada reported that at 20F (IIRC the AAA temp) they were seeing about a 20% loss. At -15F they were seeing the 40% loss reported by AAA.
     
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  15. Salamander_King

    Salamander_King Senior Member

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    I think most EV owners (BEV and PHEV) already know the effect of cold on EV range and how to deal with it. All they need is n=1 sample to conceive the effect. The big question is would this type of information keeps those who have never driven EV to stay away from EV entirely? Those people who never learned to turn down the thermostat setting in the middle of winter may never adapt. sigh :cry:
     
  16. hill

    hill High Fiber Member

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    iirc - the pip won't run ev mode that low .... whereas the soon-to-be-no-longer-produced 2019 Volt will run EV mode until it's cold soaked to around -13°f.
    .
     
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  17. El Dobro

    El Dobro A Member

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    Most EV owners, but not all. At the Chevy dealer where I bought the Volt, a Bolt owner came in, complaining how the range is only 150 miles. The tech told me when he checked it out, the seat heaters were on, the heated steering was on and the heater was set to 85 degrees. They tried explaining the problem to the customer, but the guy wouldn't believe them. :rolleyes:
     
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  18. Salamander_King

    Salamander_King Senior Member

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    I bet he has his house heat set at 85F all winter long and sleep naked with no blanket. lol
     
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  19. john1701a

    john1701a Prius Guru

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    Exaggeration serves no purpose.

    Here's PiP driving in EV without engine warm-up at -2°F




    Remember, the purpose of using the engine is for the best balance of available resources... something Volt did not do. Why carry an engine, then go to extremes to avoid ever using it?

    In other words, EV driving is possible, just not the best overall choice.
     
    #19 john1701a, Feb 10, 2019
    Last edited: Feb 10, 2019
  20. hill

    hill High Fiber Member

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    i never intended anyone to presume there is a low point best used for ev vs ICE .... & if ther is .... i never presumed to hint ibknow what it is - rather the fact remains both have diffetentvliw temps that require ICE running. If - 2° versus -13° is better, for one or worse for the other? Please State why that is or isn't the best efficiency, because I don't know - other than that's what each does.
    .
     
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