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posted by Fnord666 on Thursday May 16 2019, @04:11PM   Printer-friendly
from the your-mileage-may-vary dept.

Autoweek (and other car news outlets) summarize some independent testing: https://autoweek.com/article/green-cars/how-much-does-cold-weather-cut-electric-vehicle-range-quite-bit-aaa-study-finds

AAA partnered with the Automotive Club of Southern California's Automotive Research Center for its tests, which allowed it to run drive-simulating dynamometer tests in 20-, 75- and 95-degree Fahrenheit temperatures in a controlled laboratory setting. This is way more scientific than anything we'd be able to achieve toodling around in an EV in Detroit the next time a polar vortex hits.

A handful of key points pulled from the report:

- The increased use of HVAC systems in extreme temperatures has a bigger impact on EV range than decreases in battery pack efficiency caused by the temperatures themselves.

- Moreover, while both extremely hot and extremely cold temperatures affect range, you'll incur a significantly larger penalty when heating up a cabin than you will cooling one down. Compare that 41 percent decrease at 20 F to a mere 17 percent decrease at 95 F.

- The BMW i3s saw the biggest reductions in range in both hot and cold conditions, losing 50 and 21 percent of range in cold and hot conditions, respectively.

- The Nissan Leaf was the most versatile, losing 31 and 11 percent of range in cold and hot conditions, respectively.

The other test cars, Tesla S, eGolf and Chevy Bolt fell between these extremes. The article includes a link (pdf) to the original report with many more details. Worth reading if you live outside southern CA and are considering an electric car.

This AC is considering an electric car, and I'm fortunate enough to have an attached garage to keep it warm-ish, probably above freezing, even if the outside temp gets down to 0F (-18C) which is a typical low for my location. That means that any trip will start with a cool (not cold) battery & cabin...but after parking outdoors at my destination(s), I'll have a reduced range for the trip home.


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  • (Score: 2) by Snow on Thursday May 16 2019, @04:21PM (21 children)

    by Snow (1601) on Thursday May 16 2019, @04:21PM (#844324) Journal

    We have two cars. It makes sense to me to have one of them be electric. Most of the time we just putz around the city. I probably drive ~30 km/day on weekdays. My wife does less then that. If we get an ecar that has 200km of range, even on a cold day where it loses 50%, it would be very very rare that it would not meet our needs.

    Then we would also have a gas car for travelling outside the city.

    It makes a lot of sense. I'm hoping that this massive expansion in auto batteries leads to some breakthroughs in battery tech though. I'm kinda holding off to get a generation 2 or 3 model. I'm also a little wary about how long the batteries actually last. Do I have to replace them after 8 years? My current gas car is 8 years old and seems to be ticking along nicely.

    • (Score: 3, Informative) by c0lo on Thursday May 16 2019, @04:42PM

      by c0lo (156) Subscriber Badge on Thursday May 16 2019, @04:42PM (#844333) Journal

      We have two cars. It makes sense to me to have one of them be electric.

      In context, with a nick like yours, I really doubt it.

      --
      https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
    • (Score: 2) by KilroySmith on Thursday May 16 2019, @05:08PM (6 children)

      by KilroySmith (2113) on Thursday May 16 2019, @05:08PM (#844347)

      >>> Do I have to replace them after 8 years?
      Batteries don't generally fail (although it can happen, much like an engine failure in an ICE), what happens is that over time their capacity reduces. In the Tesla world, it's expected that the batteries will still be at 90+% capacity after 200,000 miles (300,000 km). See:
      https://electrek.co/2018/04/14/tesla-battery-degradation-data/ [electrek.co]

      I love my Tesla Model 3.

      • (Score: 2) by Snow on Thursday May 16 2019, @06:42PM (3 children)

        by Snow (1601) on Thursday May 16 2019, @06:42PM (#844398) Journal

        it's expected that the batteries will still be at 90+% capacity after 200,000 miles (300,000 km).

        I'd feel more comfortable to see the actual results. There will also be more (hopefully cheaper and better) selection then too.

        • (Score: 2) by KilroySmith on Thursday May 16 2019, @06:46PM (2 children)

          by KilroySmith (2113) on Thursday May 16 2019, @06:46PM (#844401)

          >>> to see the actual results
          Well, if you had followed the link I so helpfully provided, you'll see that the data is from real-world usage, with a smattering of data going up to 250,000 km. Is that close enough for you?

          It also has data for an EV that doesn't have a temperature-controlled battery - which shows why keeping the battery happy is a good thing.

          • (Score: 2) by Snow on Thursday May 16 2019, @07:02PM (1 child)

            by Snow (1601) on Thursday May 16 2019, @07:02PM (#844413) Journal

            The sample size in the provided link is small with sparse datapoints beyond 150K kms. I'd also like to have more confidence in how the batteries hold up with Canadian winters and the constant freeze/thaw that happens here.

            If I'm going to drop $40k, I want to know it's going to work as advertised.

            However, I'm glad there are people like you that take the plunge. Someone has to lead the pack.

            • (Score: 0) by Anonymous Coward on Thursday May 23 2019, @09:05PM

              by Anonymous Coward on Thursday May 23 2019, @09:05PM (#846795)

              There's lots of good data for the chemistries being sold right now. Basically if you don't charge or discharge below 2-3 Celsius, you can expect cell life to match the published capacity drops for charge cycles. Panasonic and others publish their cell specs*, which do vary by cell chemistry and so you have to match to the pack in the vehicle you're considering.

              Freeze/thaw cycles have minimal performance on most lithium chemistry cells, so long as they're not charged/discharged while freezing but you're Canadian, you're probably used to engine warmers (and therefore, amusingly, non-electric cars with electric plugs dangling out the front).

              *they have to so that engineers can plan devices around the capacities and performance windows of the cells!

      • (Score: 2) by bob_super on Thursday May 16 2019, @08:28PM (1 child)

        by bob_super (1357) on Thursday May 16 2019, @08:28PM (#844450)

        > Batteries don't generally fail (although it can happen, much like an engine failure in an ICE), what happens is that over time their capacity reduces.

        I read that you reach a cliff effect, sometimes around 40-60%, where the most degraded modules can just short and cause the rest to not work anymore.
        That problem could be solved by having the manufacturers make the batteries modular enough that someone could change/remove the worst ones and keep driving on the remaining less-degraded ones, but we're not there yet. Right now you have to change the whole battery, which does give you essentially a new car.

        The whole repair-rather-than-replace will probably come, as usual for these kinds of things, in another decade, through a mandate of the EU.

        • (Score: 3, Informative) by Luke on Friday May 17 2019, @04:36AM

          by Luke (175) on Friday May 17 2019, @04:36AM (#844600)

          The Nissan Leaf battery is modularised and you can replace individual cells.

          You can even replace lower capacity batteries with larger units (eg put 24kW -> 30kW).

          These guys: http://evsenhanced.com [evsenhanced.com] know all about it, and have equipment available to assist with battery swaps etc.

    • (Score: 5, Interesting) by hemocyanin on Thursday May 16 2019, @05:37PM (1 child)

      by hemocyanin (186) on Thursday May 16 2019, @05:37PM (#844364) Journal

      My wife and I have a Leaf and a gas car. We live about 12 miles out of town -- the leaf is great for my regular commute and running errands. When I have to go farther, the gas car works great for that.

      I get 4.4 miles per kWh at about a dime per kWh. My gas car get 30 mpg. I use 6.8 kWh to go 30 miles -- or 70 cents to go what costs $3.70 in my gas car. I have a 220v charger -- I can go from empty to full charge in about 2.5 to 3 hrs.

      My experience with cold and hot matches the experiment above. I have found that heating the car takes way more energy than cooling it. Last winter I bought a small space heater and a half hour before I left in the morning, I would turn it on (I just ran it off regular wall power through an extension cord). That would totally defrost all the ice from the car and make the interior absorb warmth (different than just having an interior full of hot air). I would use the heated seat and heated steering wheel and I'd often even have to crack the window to let some hot air out at the start. On the way home from work, I'd just use the climate controls. When temps were in the 20s, this made a big difference in range.

      Running AC in the summer seems to have only the most minimal impact on range. I don't even think about it -- I just use it if I'm hot.

      Used Leafs with the 80-90 mile battery are very cheap, comfortable, quiet, roomy, and really zoomy. I love the car.

    • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @06:03PM (7 children)

      by Anonymous Coward on Thursday May 16 2019, @06:03PM (#844377)

      An electric car as 1 of 2 cars is a great idea. The interesting question though is ... if you can manage on a single (ICE) car, is it more eco to buy an electric car for the short runs and keep the ice car, or just use the existing ice car all the time? It's certainly *cheaper* to only have the 1 car.

      • (Score: 2) by Snow on Thursday May 16 2019, @06:44PM (1 child)

        by Snow (1601) on Thursday May 16 2019, @06:44PM (#844400) Journal

        One of the cars is my wife's. We need (well not NEED, but...) 2 cars.

        • (Score: -1, Offtopic) by Anonymous Coward on Thursday May 16 2019, @10:46PM

          by Anonymous Coward on Thursday May 16 2019, @10:46PM (#844495)

          Your wife is a car that put your open marriage in perspective

      • (Score: 2) by Farkus888 on Thursday May 16 2019, @06:52PM

        by Farkus888 (5159) on Thursday May 16 2019, @06:52PM (#844406)

        That math is a good point and the answer is almost definitely no. It mostly only matters to single people though. My wife and I need 2 cars anyway due to work schedules and location. Both of them don't need to be able to do long range trips though. We considered it heavily when we replaced her car 2 years ago but every option was too expensive for our budget or too small for her needs.

      • (Score: 2) by KilroySmith on Thursday May 16 2019, @07:40PM

        by KilroySmith (2113) on Thursday May 16 2019, @07:40PM (#844427)

        I can't imagine that the lifecycle costs (both $$ and, for example, CO2) would ever favor the second car. There's a lot of energy involved in building a car.

        That said, choosing the right EV means you don't need the second car. Tesla is the only manufacturer who provides that right now, but companies like VW are likely to get there in a few years. I own a Tesla Model 3, and it's great in town. I wake up every morning with a full "tank", and have no issues doing all the driving I need to do in a day before plugging in again at night. That would apply to a number of other attractive EVs today also - the Bolt, i3, Leaf (with the big battery), etc. However, it's also great when I want to drive 350 miles to SoCal or Page from Phoenix; I'd also have no problem if I needed to drive to Orlando tomorrow. Tesla is the only manufacturer who has solved the long distance travel issue with it's network of Superchargers - for everyone else, charging is seen as "Someone Else's Problem". Even if the manufacturer builds fast charging capabilities into the car, they certainly haven't done any work to assure that you can use that capability on a road trip.

        As a point of reference, the Cannonball Run (https://en.wikipedia.org/wiki/Cannonball_Baker_Sea-To-Shining-Sea_Memorial_Trophy_Dash) takes about 30 hours in a prepared car (60 gallons of fuel, radar detectors and jammers, relief drivers, etc) (https://jalopnik.com/meet-the-guy-who-drove-across-the-u-s-in-a-record-28-h-1454092837), about 40 hours in a stock ICE vehicle, and about 50 hours in a stock Tesla Model 3 (https://www.thedrive.com/new-cars/17312/tesla-model-3-sets-new-ev-cannonball-run-record-of-50-hours-16-minutes). So, there's a time penalty to be paid for using an EV currently, but it's not nearly as bad as people believe. I'm still waiting for someone in a Chevy or BMW or Jaguar or Audi or VW EV to even be able to make the run.
         

      • (Score: 2) by hemocyanin on Thursday May 16 2019, @11:10PM (2 children)

        by hemocyanin (186) on Thursday May 16 2019, @11:10PM (#844502) Journal

        One option if you only _need_ one car, but rarely go very far, is to rent a car for those long trips.

        I save about $3 for every 30 miles I drive my Leaf compared to the gas car. If I drive 30 miles per day, 5 days per week, that's $15/wk in gas savings, or about $780/year. I looked at budget and an intermediate size SUV is about $50/day. I'm sure there are other costs involved -- insurance, gas, whatever BS they tack on, hassle factor -- call it $75 bucks/day. Using my 30 mpg ICEcar as baseline for the cost breakdown, I would break if I had to rent a car 10x per year and lose money if I needed to rent more often than that. In my case, I do need an ICEcar more than 10x year, so that's why both cars aren't electrics.

        • (Score: 0) by Anonymous Coward on Friday May 17 2019, @07:30AM (1 child)

          by Anonymous Coward on Friday May 17 2019, @07:30AM (#844634)

          Good point - although car rental is *much* cheaper in the USA than Europe. It's also really inconvenient to hire a car when you only own one car and have to drive to get a rental. If it was once/twice a year that would work, but I need 400 miles for a weekend about 8 times a year, so the balance is off.

          • (Score: 2) by aclarke on Friday May 17 2019, @03:15PM

            by aclarke (2049) on Friday May 17 2019, @03:15PM (#844731) Homepage

            That depends on where in Europe. I've had some shockingly cheap rentals in the Netherlands and Germany.

    • (Score: 2) by JoeMerchant on Thursday May 16 2019, @08:15PM (2 children)

      by JoeMerchant (3937) on Thursday May 16 2019, @08:15PM (#844444)

      The most we ever paid for a vehicle was $19,000 for a brand new pickup truck in 1999. After that, it was $14,000 for a brand new Miata in 1991. The most expensive used car we ever bought was $12,000.

      My main beef with auto battery power is the cost of the battery packs - which can range to $20K and higher. I can't imagine an auto battery pack lasting 200,000 miles or 20 years - which both of those purchased new vehicles have done.

      --
      🌻🌻 [google.com]
      • (Score: 2) by MostCynical on Thursday May 16 2019, @09:01PM (1 child)

        by MostCynical (2589) on Thursday May 16 2019, @09:01PM (#844463) Journal

        As above [soylentnews.org] you don't have to imagine, they have already managed the distance..

        --
        "I guess once you start doubting, there's no end to it." -Batou, Ghost in the Shell: Stand Alone Complex
        • (Score: 2) by JoeMerchant on Friday May 17 2019, @02:11AM

          by JoeMerchant (3937) on Friday May 17 2019, @02:11AM (#844556)

          Put another way, by the time I put 200,000 miles on an "around town" vehicle, it's more than 20 years old - proven twice now.

          Where will those battery packs be after 20 years of hot/cold charge/discharge water ingress, and other real-life challenges?

          I know Lithium-Iron is better (and more expensive), than Lead-Acid, but the very same concern has kept me away from the lead-acid battery vehicle market - at least for big four+ seaters. On the other hand, I pretty much love my fat-tired electric bike, even if its Lithium-Iron battery pack has noticeably degraded already in less than a year of use, it's only a few hundred dollars to replace.

          --
          🌻🌻 [google.com]
  • (Score: 5, Interesting) by Anonymous Coward on Thursday May 16 2019, @04:49PM (17 children)

    by Anonymous Coward on Thursday May 16 2019, @04:49PM (#844335)

    I don't get it.

    What are tests such as these always fundamentally broken.

    I looked at the PDF. It's here:

    https://crain-platform-autoweek-prod.s3.amazonaws.com/s3fs-public/AAA-Electric-Vehicle-Range-Testing-Report.pdf [amazonaws.com]

    I read the PDF, hunting for details, and came across this...

    For each vehicle, instrumented dynamometer tests were performed under the following conditions:
    1) Ambient temperature of 75°F and climate control switched off
    2) Ambient temperature of 95°F and climate control switched off
    3) Ambient temperature of 95°F and climate control switched on
    4) Ambient temperature of 20°F and climate control switched off
    5) Ambient temperature of 20°F and climate control switched on

    OK, great. What does "climate control" on or off mean? Most importantly, at what temperature is climate control set to?

    As testers, you can get this info from manufacturers. Fancy cars let you set precise temps, eg 21C or 70F or whatever..

    But it's just "on" or "off". No indication of what the dial was set to. No idea how it was setup. I scanned the doc, and this info doesn't seem to be provided.

    Why is this important?

    Well.. outside of the laboratory, the real world is different. At -30C, when I get in my car in the winter -- sure, I turn on the heat. But to 20C? I'd *roast* in my winter coat, boots, and such.

    No, I typically might heat the car to 0C or so. Even that gets toasty after too long.

    So in the real world (not like California, where 50F is "cold" and requires a coat), people adapt. And they're wearing clothing that is prohibitive to using climate control at 70F or what not.

    And I'm sure the same goes for A/C. If you're wearing shorts, you live in Arizona, and it gets down to a chilling 80F in the winter, well :P Probably "A/C" is to keep it under 90F or whatever, heh.

    This is important, because it will impact how people think of vehicle usage "for them". And without an indication of what temperature, what setting? We can't guess how it would affect us.

    Worse?

    Each car is different. Some cars will have 75F at 'centre' position for climate control, others maybe 68F. That counts. That might count a lot, for cars with smaller battery packs.

    Sigh.

    I'd almost think the study was done with the backing of the oil industry... but it's just sheer incompetence, surely.

    • (Score: 2) by NewNic on Thursday May 16 2019, @05:05PM (10 children)

      by NewNic (6420) on Thursday May 16 2019, @05:05PM (#844345) Journal

      In my Leaf, you can turn off the cabin heater and A/C. You can control the fan independently. So, while there is no single on/off switch, it can be effectively switched off. I think the same is true for most cars.

      --
      lib·er·tar·i·an·ism ˌlibərˈterēənizəm/ noun: Magical thinking that useful idiots mistake for serious political theory
      • (Score: 2) by KilroySmith on Thursday May 16 2019, @05:12PM

        by KilroySmith (2113) on Thursday May 16 2019, @05:12PM (#844351)

        I think the point is that AAA probably put the climate control system on some standard temperature like 20C, which gives pessimistic data relative to real-world degradation usage. If you've got a coat on, you probably have your climate control set to (perhaps) 0C in the Chicago winter, and not 20C.

      • (Score: 2) by hemocyanin on Thursday May 16 2019, @11:13PM (8 children)

        by hemocyanin (186) on Thursday May 16 2019, @11:13PM (#844503) Journal

        My 2012 leaf has a labeled button on the dash to totally turn off/on climate controls. When it is on, you can set desired temp, fan, AC, which vents are used. Off just shuts it all down.

        • (Score: 2) by NewNic on Thursday May 16 2019, @11:36PM (7 children)

          by NewNic (6420) on Thursday May 16 2019, @11:36PM (#844515) Journal

          I'll have to look at the controls of my 2016 Leaf.

          --
          lib·er·tar·i·an·ism ˌlibərˈterēənizəm/ noun: Magical thinking that useful idiots mistake for serious political theory
          • (Score: 2) by hemocyanin on Thursday May 16 2019, @11:47PM (6 children)

            by hemocyanin (186) on Thursday May 16 2019, @11:47PM (#844519) Journal

            If this picture accurately shows a 2016 model's climate controls, the button right below the big silver "auto" button is the kill switch: https://images.hgmsites.net/lrg/2016-nissan-leaf-4-door-hb-sl-temperature-controls_100539211_l.jpg [hgmsites.net]

            I wonder if it really is a 2016 -- that looks exactly like my 2012 climate control panel. But I suppose with a low volume car like that, they didn't do much fiddling.

            • (Score: 2) by NewNic on Friday May 17 2019, @12:00AM

              by NewNic (6420) on Friday May 17 2019, @12:00AM (#844526) Journal

              That looks nothing like the controls on my 2016 Leaf.

              --
              lib·er·tar·i·an·ism ˌlibərˈterēənizəm/ noun: Magical thinking that useful idiots mistake for serious political theory
            • (Score: 2) by NewNic on Friday May 17 2019, @12:05AM (4 children)

              by NewNic (6420) on Friday May 17 2019, @12:05AM (#844533) Journal

              Page 180 on this document:
              https://cdn.dealereprocess.net/cdn/servicemanuals/nissan/2016-leaf.pdf [dealereprocess.net]

              Mine is the "Type A" and it does have an off switch.

              --
              lib·er·tar·i·an·ism ˌlibərˈterēənizəm/ noun: Magical thinking that useful idiots mistake for serious political theory
              • (Score: 2) by hemocyanin on Friday May 17 2019, @05:09AM

                by hemocyanin (186) on Friday May 17 2019, @05:09AM (#844607) Journal

                That's weird -- It doesn't make any sense to disable a power saving function. I wonder what knucklehead was responsible for that.

              • (Score: 2) by hemocyanin on Friday May 17 2019, @05:13AM (2 children)

                by hemocyanin (186) on Friday May 17 2019, @05:13AM (#844609) Journal

                Look at page 4-26. It appears that the left side knob can be pressed to turn the system off -- see note 11.

                • (Score: 2) by NewNic on Friday May 17 2019, @05:17PM (1 child)

                  by NewNic (6420) on Friday May 17 2019, @05:17PM (#844782) Journal

                  What part of "it does have an off switch." wasn't clear?

                  --
                  lib·er·tar·i·an·ism ˌlibərˈterēənizəm/ noun: Magical thinking that useful idiots mistake for serious political theory
    • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @05:15PM

      by Anonymous Coward on Thursday May 16 2019, @05:15PM (#844353)

      "No, I typically might heat the car to 0C or so. Even that gets toasty after too long."

      Maybe for short trips, but for longer drives people aren't keeping their cars at freezing. You're right, they should have specified, you could say implicitly that their climate controls were set to 75 degrees F and I don't think that's typical.

    • (Score: 3, Informative) by NewNic on Thursday May 16 2019, @06:04PM (4 children)

      by NewNic (6420) on Thursday May 16 2019, @06:04PM (#844379) Journal

      OK, great. What does "climate control" on or off mean? Most importantly, at what temperature is climate control set to?

      The document states that the climate control was set to 72F, but there is some discrepancy between cars about the setting of recirculation and fan.

      The tests used an unrealistic setting of maximum fan speed, but only for cars where this could be set without taking the climate control out of auto mode.

      --
      lib·er·tar·i·an·ism ˌlibərˈterēənizəm/ noun: Magical thinking that useful idiots mistake for serious political theory
      • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @06:11PM (3 children)

        by Anonymous Coward on Thursday May 16 2019, @06:11PM (#844383)

        Thanks for finding this. I read the summary, the initial pages with the above info, read a bunch of pages after, and tried to scan for "temp patterns" in the rest.

        Guess I missed this. At least we know it's 72F, and I don't know anyone that sets their car to 72F, when it's the winter. Only exclusion is if one is going to be driving for 10 hours or some such, and you might take your coat off.

        But most people don't take their winter coat off, to drive even a few hours. Why bother? So I wish they'd have redone the test at cooler temps internally :(

        • (Score: 2) by dry on Friday May 17 2019, @05:44AM (2 children)

          by dry (223) on Friday May 17 2019, @05:44AM (#844624) Journal

          I see lots of people wearing fuck all in the winter here in Canada. They're nuts as all it takes is a break down or snow bank on the road and they'll freeze. Now this is the warm part of Canada, but minus 10C is still cold enough to freeze.

          • (Score: 2) by aclarke on Friday May 17 2019, @03:20PM (1 child)

            by aclarke (2049) on Friday May 17 2019, @03:20PM (#844735) Homepage

            I often don't wear a jacket in the car, or walking from my car to whatever building I'm going into, etc. I park my car in the garage, so why would I put on a coat? I do, however, carry safety gear in the car, so in an emergency, if I'm not wearing a coat, I'll just pull it out of the back of the vehicle.

            While I agree many people drive without safety gear, just because you don't see them wearing it in the car, it doesn't mean they don't have it.

            • (Score: 2) by dry on Friday May 17 2019, @03:30PM

              by dry (223) on Friday May 17 2019, @03:30PM (#844739) Journal

              The other year, a bunch of traffic got trapped by a snowbank, couple of dozen vehicles. There were 2 people who were prepared, and one was a cop. They were lucky a farmer took them in.

  • (Score: 3, Interesting) by KilroySmith on Thursday May 16 2019, @05:02PM (12 children)

    by KilroySmith (2113) on Thursday May 16 2019, @05:02PM (#844343)

    In the Tesla world, owners mitigate the cold weather range loss by using the seat heaters (and in the Model S/X, the steering wheel heaters) rather than the cabin heater. They say they can be just as comfortable with significantly less power expenditure. Living in Phoenix, I haven't tested this for myself...

    The thing that I don't understand is why Tesla uses inefficient resistive heating for cabin heat. In moderate temps (say, above 0C), using the already-installed A/C system as a heat pump to heat the cabin would be much more efficient at a small cost (inclusion of a reversing valve in the refrigerant line). Admittedly, it IS an additional cost because they'd have to have the resistive heater anyway for lower temps, but Tesla isn't about squeezing pennies here and there...

    • (Score: 3, Disagree) by c0lo on Thursday May 16 2019, @05:17PM (5 children)

      by c0lo (156) Subscriber Badge on Thursday May 16 2019, @05:17PM (#844356) Journal

      nefficient resistive heating for cabin heat. In moderate temps (say, above 0C), using the already-installed A/C system as a heat pump to heat the cabin would be much more efficient at a small cost

      Really? I think you'll discover that using electricity to drive a heat pump to heating and using the same electricity through a resistor will favor the latter in terms of efficiency.

      --
      https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
      • (Score: 4, Informative) by Immerman on Thursday May 16 2019, @05:46PM

        by Immerman (3985) on Thursday May 16 2019, @05:46PM (#844368)

        Actually no. It'll depend on just how cold it actually is, but in general a heat pump is much more efficient that direct heating - essentially you're using maybe 100W of energy to move 300W of heat from a cold place to a warm place - giving you 200W of heating for "free".

      • (Score: 2) by KilroySmith on Thursday May 16 2019, @05:56PM

        by KilroySmith (2113) on Thursday May 16 2019, @05:56PM (#844374)

        A heat pump in relatively moderate conditions (0C) will be about 3 times more efficient than electric heating, but rapidly loses efficiency below there. Units can be built to operate much, much colder, but then they don't work (or work well) for cooling.

      • (Score: 4, Informative) by Arik on Thursday May 16 2019, @06:11PM (1 child)

        by Arik (4543) on Thursday May 16 2019, @06:11PM (#844384) Journal
        The glory and the downfall of the heat pump is right there in the name.

        It doesn't heat or cool, it just transfers hot or cold from one place to another.

        If you want to cool, then it needs somewhere to dump heat. A radiator, more or less. It makes you cool by transferring the heat from where you are, to the radiator. The colder that radiator on the outside is, the more efficient this process becomes. But if the radiator is hot, then this doesn't work well at all.

        And it works exactly the same in reverse. If you want to *heat* the inside of the car with a heat pump, then you're still going to be using the radiator to do it, only now the HOTTER the radiator the better it works.

        In an internal combustion engine, this can still work fine, even in nasty cold weather. That engine has to thermal cycle and build up a good bit of thermal energy to reach operating temperature, and it keeps right on making heat afterwards which must be radiated away. If you don't use that to heat up the car then it will have to be radiated out another way anyway.

        One of the nice things about electric motors in other contexts is that they *don't* really put out much heat. Yes, there's friction, there's some radiation of thermal energy, but it's nothing like what happens with an internal combustion engine, there's no getting up to operating temperature and heat radiated is much less. In warm weather this is great, it means you aren't wasting a lot of energy heating up that engine block. In cold weather, though, it means you can't rely on the engine as a source for heat.

        --
        If laughter is the best medicine, who are the best doctors?
        • (Score: 2) by aclarke on Friday May 17 2019, @03:23PM

          by aclarke (2049) on Friday May 17 2019, @03:23PM (#844737) Homepage

          Air-to-air heat exchangers are pretty well-proven technology. They're a fairly efficient way to heat, even in freezing temperatures, although their efficiency drops with the temperature, just as an air conditioner's efficiency drops as temperature rises.

          Perhaps they're too bulky or heavy or expensive to put into a car, but they're used regularly in buildings.

      • (Score: 0) by Anonymous Coward on Thursday May 23 2019, @09:11PM

        by Anonymous Coward on Thursday May 23 2019, @09:11PM (#846799)

        LOL.

        Reread what you said.

        The heat pump IS a "resistor" in terms of converting electricity to heat.

        A heat pump running at 0% efficiency is precisely a resistive heater, with 100% electric to heat conversion.

        A heat pump running at >0% efficiency and sucking the same juice radiates the same heat due to resistance AND pumps heat in from the outside.

        A heat pump, even the literal least efficient so long as it's not being run 'backwards', will ALWAYS outperform resistive heating.

        The only argument you could POSSIBLY make against them is that they take material to make and to lug around, and maybe they're too heavy to be practical (not the case, but you could argue it).

        Learn some basic physics. Heat pumps don't violate conservation of energy.

    • (Score: 2) by bussdriver on Thursday May 16 2019, @05:51PM (2 children)

      by bussdriver (6876) Subscriber Badge on Thursday May 16 2019, @05:51PM (#844372)

      Resistance heating wastes almost no energy... a heat pump loses a fair amount of energy pumping gas into liquid and I suppose you could put the motor into the car so the lost heat goes into the car (not helping in summer.)

      More fundamental: heat pumps MOVE temperature. In summer, you have cool air rushing past a radiator at high speeds so moving heat away is easy to do that is FREE cooling (within the loop; obviously ignoring that the car has to move itself.) In winter, you have cold air rushing past a radiator trying to extract heat so the compressor has to work more to get less. You can't place the warm loop into the ground to get FREE heat because it's a car. Best you can do is place a black glass covered radiator on the roof of the car (solar heater.)

      • (Score: 3, Informative) by Immerman on Thursday May 16 2019, @06:39PM

        by Immerman (3985) on Thursday May 16 2019, @06:39PM (#844396)

        It's true there's little waste - heating is typically very close to 100% efficient, because heat is the thermodynamic waste-pit of the universe.

        However, being 100% efficient at what it does (generating heat), doesn't mean that what it's doing is the most efficient way to accomplish what you actually want (heating an area). A heat pump can be much more efficient because rather than generating heat, it's consuming energy to move heat from someplace cool to someplace warm. So long as that temperature difference isn't too great (and humans can't actually survive a very large temperature range), 1kW of mechanical work can move several times than much heat.

      • (Score: 5, Informative) by KilroySmith on Thursday May 16 2019, @06:53PM

        by KilroySmith (2113) on Thursday May 16 2019, @06:53PM (#844408)

        Resistance heating has an efficiency of 1 or 100% (kinda by definition). Every watt of power going into it generates a watt of heat.

        Within their rated temperature range, a heat pump has an efficiency of 3 to 6 - 300% to 600%. Every watt of power going into it (compressing and pumping gas) generates the equivalent of 3 to 6 watts of heat/cold. In Phoenix, all of our Air Conditioners (kinda required for summer) are Heat Pumps, and are used for heating the houses in the winter. Older models used to have resistance heaters piggy-backed on that only ran when the temperature got below freezing - and boy did people hate it when the electric bill came. Newer units continue to operate down to the lowest temperatures we see out here (maybe 25F) so the resistance heaters have disappeared.

    • (Score: 2) by Immerman on Thursday May 16 2019, @06:55PM (2 children)

      by Immerman (3985) on Thursday May 16 2019, @06:55PM (#844411)

      >using the already-installed A/C system as a heat pump

      The question I would ask is, is the AC actually a viable heat pump? In theory there's very little difference between a refrigeration unit and a general-purpose heat-pump, but in practice... practical design choices and optimizations (like the optimal thermal range of the refrigerant) can often make a refrigeration unit unsuited for pumping heat in the other direction. Rather like a claw hammer and a crowbar - both do basically the same thing, pounding on things and pulling them apart, but they're optimized for opposite jobs, and you have to work way too hard to use the one where the other is called for.

      My understanding is that a bi-directional heat pump is typically considerably more expensive than a dedicated AC - and I assume there's good reason for that. And as you allude to, heat pumps become a lot less effective when it gets really cold, which means you still need all the resistive heating in addition to a more expensive heat pump.

      • (Score: 2) by Arik on Thursday May 16 2019, @07:40PM (1 child)

        by Arik (4543) on Thursday May 16 2019, @07:40PM (#844428) Journal
        "My understanding is that a bi-directional heat pump is typically considerably more expensive than a dedicated AC - and I assume there's good reason for that."

        Sure, and the reason you mentioned (optimal refrigerant for cooling versus compromise choice that will work for both) may well be part of it, it makes sense. But a bigger part is on the external end. For ideal efficiency you want both a hot source and a cold source. A shaded radiator and blower outside normally works fine for just cooling, but the problem is when you want to heat in the winter that's not very efficient at all. So what do you do? Add an entirely different endpoint for heating in winter? A lot of extra work and material but ok, where, how?

        A thermosolar collector, for instance, would work well during the day, but it would cool down mighty quickly after sunset. You can moderate that effect by including a really big heat sink, but of course that makes it all the more expensive.

        If you happen to have built next to a hot spring, well that's just great, use that, but most places that's not an option.

        So what you might see in a high end system is they'll bury the radiator several feet underground. Actually works pretty well, the temperature stays pretty consistent if you bury it nice and deep, in a range where it can both cool in summer and heat during winter with reasonable efficiency. Helps to narrow down the range of temperatures your refrigerant will encounter too, I would imagine. But it's expensive, and difficult to access for maintenance or repair.

        Now, in a conventional car, with an ICE, it actually makes a lot more sense to just use two endpoints. You have a hot engine block and a cool radiator very close together.

        It makes sense, but I'm not sure how often it's really done. As far as I know car heaters more often just intake hot air from off the engine block instead of using a heat pump. I'm far from expert on cars though.

        With an electric vehicle, however, you don't have that engine block for a ready source of heat, so in that case it doesn't even make sense.

        --
        If laughter is the best medicine, who are the best doctors?
        • (Score: 2) by dry on Friday May 17 2019, @06:01AM

          by dry (223) on Friday May 17 2019, @06:01AM (#844627) Journal

          Cars usually are water cooled and have plumbing and a small radiator in the cab or firewall area with a fan that blows air through the small radiator (heater core) into the cab. Vans and such might have pipes going to the rear and another heater core back there. There's also a thermostat that isolates the radiator until it's needed to cool down the engine. In really cold conditions, the radiator might never get hot.
          I'm old enough to remember the original Volkswagen Beetles with air cooled engines, total bitch to heat, they actually had gas (petrol) powered heaters. This might be another option, an alcohol or such powered auxiliary heater in really cold climates.

  • (Score: 1, Informative) by Anonymous Coward on Thursday May 16 2019, @05:08PM (2 children)

    by Anonymous Coward on Thursday May 16 2019, @05:08PM (#844348)

    The chevy bolt went from 114 MPGe to 65 MPGe at 20 degrees F when running the heater. Cold climate shoppers need to take this into account when doing a full cost analysis against gas guzzlers which give you free heat.

    • (Score: 1) by jlv on Thursday May 16 2019, @06:07PM (1 child)

      by jlv (3756) on Thursday May 16 2019, @06:07PM (#844381)

      I've driven only BEVs for 5+ years. IMHO, MPGe is a useless number.

      • (Score: 1, Insightful) by Anonymous Coward on Thursday May 16 2019, @06:15PM

        by Anonymous Coward on Thursday May 16 2019, @06:15PM (#844386)

        Use whatever units you want, when keeping the car warm doubles the amount of electricity used it puts a serious damper on the value proposition.

  • (Score: 2, Informative) by jlv on Thursday May 16 2019, @06:21PM (1 child)

    by jlv (3756) on Thursday May 16 2019, @06:21PM (#844388)

    Background: I had a LEAF for 5 years and 34K miles. I currently drive an S (34K miles in 2 years) and my wife drives an X (just 6 months old). We are 100% BEV. No ICE cars for us. We live in New England and the winter temps regularly get to 10°F-20°F range. Maybe one or two 0°F a year.

    Seat heaters and steering wheel heaters are a must. That allows you to avoid wasting power heating the cabin air. This works reasonably well until it's near freezing, when I personally want more warmth.

    What also matters is the type of heater in the car. My LEAF (2013 SL) had a hybrid heat-pump/resistive heater. It is much more efficient at temps > about 15°F. Both our Tesla's only have resistive heaters. That makes them consume more power.

    In the LEAF, winter driving range took a huge hit because of the small battery. 75 miles range in the summer, 50 miles range when using heat continuously. It really doesn't matter too much if you set the heat up high or low; the power consumption is steep just using the heater, and raising the setpoint from 66°F to 72°F only increases the power from about 1600W to 2000W.

    In the Tesla, generally I don't care about the range hit. In average daily driving I have more than enough range and I'll just charge it up when I get home. I never think about it.

    However, one trip where it mattered was a drive to Buffalo, NY, for Christmas where there was an ice storm covering upstate NY. Normally this trip requires us to make 2 SuperCharging stops of 20 minutes each. There were 4 of us in the S and we were running the heat continuously. That alone wouldn't have affected our trip for more than 5 minutes of extra SuperCharging. However, the snow/ice caused our driving efficiency to drop by 20%. All combined, it meant we needed an extra SuperCharging stop of 20 minutes in the middle of the trip.

    • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @08:08PM

      by Anonymous Coward on Thursday May 16 2019, @08:08PM (#844439)

      Let me guess, when you got to Buffalo, you stopped at the Supercharger at Clarence Mall, next to Eastern Hills Mall? Barnes & Noble store nearby and about a half mile from this AC's house. Don't think I've ever seen more than three Teslas charging at once at that location.

  • (Score: 3, Interesting) by Phoenix666 on Thursday May 16 2019, @06:26PM (1 child)

    by Phoenix666 (552) on Thursday May 16 2019, @06:26PM (#844390) Journal

    I'd like to see more studies like this conducted by more neutral parties. Triple-A is an organization that champions the ICE. The magazine they send around to members was filled with regular hit pieces on electric cars as recently as four years ago.

    EVs have been selling like hot cakes in Norway, which is about as cold and mountainous as it gets, so they're probably a better barometer of how well EV range performs in weather.

    --
    Washington DC delenda est.
    • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @08:10PM

      by Anonymous Coward on Thursday May 16 2019, @08:10PM (#844442)

      Huge incentives to purchase a BEV in Norway, compare to neighbors Sweden and Finland -- same climate, no incentive and relatively low BEV sales. Iirc, Denmark(??) was a big market for Tesla until the government incentives were cut off and then sales collapsed.

  • (Score: 2) by ledow on Thursday May 16 2019, @06:55PM (6 children)

    by ledow (5567) on Thursday May 16 2019, @06:55PM (#844410) Homepage

    "This AC is considering an electric car, and I'm fortunate enough to have an attached garage to keep it warm-ish, probably above freezing, even if the outside temp gets down to 0F (-18C) which is a typical low for my location. That means that any trip will start with a cool (not cold) battery & cabin...but after parking outdoors at my destination(s), I'll have a reduced range for the trip home."

    Surely... you'll have a reduced range for the entire trip. The battery either needs to be heated (draining said battery) or will be pretty much the same temperature as the outside.

    It's not like an ICE car where the burning of fuel automatically heats the whole engine and getting RID of heat is your problem. In an EV, there's little heating besides what you deliberately cause (braking and moving-part friction aside).

    If it's cold, no matter where you *kept* it, from when you start your journey, it's going to get cold or use power to keep warm. Sure, leaving it 8 hours in the cold at the other end won't help, but you're going to lose range from the second it leaves a warm garage.

    In sub-zero temperatures, it would be mere minutes without heating before the battery is being cooled by the outside air / sucking heat from the cabin.

    • (Score: 2) by Arik on Thursday May 16 2019, @07:22PM (1 child)

      by Arik (4543) on Thursday May 16 2019, @07:22PM (#844420) Journal
      Seems like this could be partially alleviated by housing the battery so it shares cabin heat and is at least as well insulated from the outside as the rest of the cabin.

      Could this be a problem in summer though? These batteries actually produce a little heat as they are discharging, don't they?
      --
      If laughter is the best medicine, who are the best doctors?
      • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @08:56PM

        by Anonymous Coward on Thursday May 16 2019, @08:56PM (#844460)

        And battery fires are good reasons to keep them on the outide of the firewall.

    • (Score: 2) by NewNic on Thursday May 16 2019, @07:33PM

      by NewNic (6420) on Thursday May 16 2019, @07:33PM (#844424) Journal

      Model 3s use waste heat from the motors to heat the battery. There is no dedicated battery heater: if the car isn't moving and it needs to heat the battery, the motors are used as pure heaters.

        It's possible that the newest Model S and X cars also do this.

      --
      lib·er·tar·i·an·ism ˌlibərˈterēənizəm/ noun: Magical thinking that useful idiots mistake for serious political theory
    • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @08:30PM

      by Anonymous Coward on Thursday May 16 2019, @08:30PM (#844452)

      > Surely... you'll have a reduced range for the entire trip. The battery either needs to be heated (draining said battery) or will be pretty much the same temperature as the outside.

      Not quite, these batteries have some internal resistance, so they self-heat to some extent when discharging and when charging. They also have a lot of thermal mass, my guess is that after leaving the garage (warmer than ambient), battery temp might stay about the same delta above ambient while driving. Then start to cool when the car is parked at the first destination.

      Slightly related example: We have a little electric lawn mower that runs on 40V li-ion battery packs (about 2x the pack on a battery powered drill). When we mow, the battery comes out warm. If we try to charge right away, the charger flashes red = too hot to charge, and we have to wait for the battery to cool before charging. As an experiment, I've rotated between our four battery packs (came with two, we bought a spare and also a trimmer using same pack) well before they show 0 bars (4 bars is full charge). If I take the battery out at 2 bars and swap in a fresh battery, the first one will gain a bar (to 3) as it cools sitting in the shade. The temp sensitivity is very real.

      For anyone considering an electric car, and with a small-ish lawn, I strongly suggest getting your toe in the water with a battery mower. The lack of vibration & noise compared to a single cylinder ICE makes a world of difference--I don't hate mowing anymore.

      The same battery is also available with a little snow blower, but the sales guy didn't recommend it, power required is a lot more and the run time only a few minutes for this combination. So we still have a gasoline container in the garage for the snowblower... When this mower dies (already ~4 years old) maybe the replacement will use a larger battery pack, and a battery powered snowblower will make sense.

    • (Score: 0) by Anonymous Coward on Thursday May 16 2019, @09:34PM (1 child)

      by Anonymous Coward on Thursday May 16 2019, @09:34PM (#844477)

      Background: Chevy Volt owner for 3 years in MA.

      Keeping the car in the garage won't help in cold weather (maybe unless your garage is heated). After 5 mins in the cold, the ICE will start until the batteries are warm enough.
      I can commute all on batteries in the summer, but have to put gas in the winter. It's still worth it.

      • (Score: 0) by Anonymous Coward on Friday May 17 2019, @03:57AM

        by Anonymous Coward on Friday May 17 2019, @03:57AM (#844584)

        Interesting, the Volt battery pack goes from what, ~30 miles range at 20C/70F in summer to 5 miles in your winter situation? That is really a huge hit. At 5 miles it gets hard to call the Volt a plug-in hybrid.

        Is your garage attached to the house? Mine shares two heated walls with the house, common unheated attic overhead, earth temp floor (~50 F around here) and the double-wide overhead door and one wall with the outside, so it is at a temp about half way between outside and inside temp.

        Still think that larger (BEV) batteries might stay warm longer if stored in a garage like mine. If nothing else they have a lower surface:volume ratio, just because they are physically larger.

  • (Score: 2) by lentilla on Friday May 17 2019, @05:24AM (3 children)

    by lentilla (1770) on Friday May 17 2019, @05:24AM (#844613)

    Now I realise this might be politically difficult but what about putting a kerosene (diesel) heater in electric cars? On really cold days, instead of using an electric heater, you just fire up the kero burner and the cabin stays toasty warm. It shouldn't take up too much space - a burner, an air-exchange unit, a fan and a few litres of fuel.

    Perhaps somebody could make a back-of-the-napkin calculation/guess as to how much fuel this would burn per hour? A number of people on this thread have suggested they want to heat from 0°F (ambient) to 32°F (cabin), so that sounds like a reasonable place to start. I am guessing (and of course I may be very wrong) that the amount of fuel used to heat the cabin would be a single digit percentage of what would have been used as fuel to power an internal combustion engine.

    • (Score: 2) by Phoenix666 on Friday May 17 2019, @01:43PM

      by Phoenix666 (552) on Friday May 17 2019, @01:43PM (#844695) Journal

      We solved that issue out West 30 years ago. battery powered socks, thermal underwear, and a thermos of hot coffee.more than enough to keep a driver warm. And when you get out of the car, you are still just as warm.

      --
      Washington DC delenda est.
    • (Score: 0) by Anonymous Coward on Friday May 17 2019, @02:54PM

      by Anonymous Coward on Friday May 17 2019, @02:54PM (#844720)

      Pick a better fuel--gasoline or diesel fuel don't burn very cleanly (thus emission control systems on cars). Someone earlier mentioned alcohol which might be a good choice, propane would be another good choice.

      Years ago a friend added a gasoline heater to his original VW Beetle (air cooled engine). The heater was in the front trunk and the exhaust out the side of the car was pretty smoky, it ran very rich (fuel:air ratio) for some reason we never figured out. Kept the car warm all right. The gas came from the main tank (also in front) and it did cut into gas mileage noticeably.

    • (Score: 2) by aclarke on Friday May 17 2019, @03:33PM

      by aclarke (2049) on Friday May 17 2019, @03:33PM (#844741) Homepage

      Interesting idea. You could put one of these in a BEV I suppose: https://www.webasto-comfort.com/int/heating/car-parking-heater/ [webasto-comfort.com] . My car's a PHEV though so I sort of have that built in.

      I've always wanted a Webasto or Eberspacher diesel-fired heater in my classic Land Rover though. I just never wanted to spend the huge amount of money it was going to cost.

  • (Score: 2) by aclarke on Friday May 17 2019, @03:11PM

    by aclarke (2049) on Friday May 17 2019, @03:11PM (#844728) Homepage

    With my 2017 Ford C-Max Energi (PHEV), my best-case range estimate has been 32km around maybe 15C, and my worst-case has been 17km when it's below -20C. So at worst I get 53% of my best-case scenario. Most of the year, it's between 20-30km.

    Over the course of a year, with the sort of driving I do, I average 3.6 l/100km. It's a lot better in the summer and a lot worse in the winter.

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