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Winter & Cold Weather EV Range Loss in 7,000 Cars

recurrentauto.com

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Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#51

Post by jakewins »

In the end it’s not clear to me that the winter range reduction will matter; battery learning rate is about 20% per production doubling, and there must be another 2-3 doublings (or more?) before the sigmoid levels off.

So, by the time 50%+ of new cars in US are EV, you can buy something with 2-3x the range of today at todays price point.

And the range today is not bad; on Friday I drove 200 miles in my Kona, in 5F with winter tires, stopped to eat and then drove another 200 miles.. like, road tripping is for sure less smooth than with gasoline, but it’s marginally worse, not show stopper, and is gap rapidly closing.

Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#52

Post by mrits »

j33zusjuice wrote: post #34
crazygringo wrote: post #16

I find it strange that the charts only go down to 20°F, when for example at the moment I write this comment, it's -5°F (-21°C) in Bismarck, North Dakota. And sub-zero Fahrenheit temperatures are pretty common in the winter across the Northeast, especially at night. "Normal" driving conditions extend way below just 20°F.

I don’t understand it either. Lows well under 20°F are fairly common in the US. The _average_ temperature in the winter is in the mid-20s where I currently live.

We are sub 20F next week in Austin,Tx. I'm going to IL for the holidays where it looks like will be -7F for Christmas.

Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#53

Post by Hamuko »

St-Clock wrote: post #33
cameronh90 wrote: post #30

My fuel economy drops about 20% on my petrol car in cold weather city driving. I don't know what causes the difference, perhaps waiting for the car to warm up and windows to defrost.

Winter tire (if you have them) and heating are the likely culprits!

Heating shouldn't take any fuel efficiency in a petrol-powered car since the heat is (usually) just a by-product of the engine's inefficiencies.

Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#55

Post by anamexis »

xyzzyz wrote: post #39
anamexis wrote: post #15

Earlier quoted context omitted.

Are you suggesting there is nearly zero difference in battery range in cold weather? Because that seems like something you can trivially look up as well. Heaters use power. Plenty of other articles seem to back up the ~20% loss for Teslas, such as: https://www.carscoops.com/2021/01/how-much-worse-is-a-tesla-... One interesting thing that points out is that internal combustion engines are also about 15% less efficient…

> One interesting thing that points out is that internal combustion engines are also about 15% less efficient at cold temperatures. They are less efficient at cold engine temperatures, but more efficient at cold air temperatures. This means that in cold winter, once the engine warms up (which might not take place on short routes), internal combustion engines are more efficient than in summer.

That may well be, but it seems like the 15% is a high-level number that takes a lot of factors into account, such as power used by heating accessories, and the fact that cold air is denser (more air resistance).

https://www.fueleconomy.gov/feg/coldweather.shtml

My original wording was inaccurate, as it's more about ICE-powered vehicles than the engines themselves.

Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#56

Post by sitkack »

It is too bad they don't have the estimated reduction next to the actual, then we could reason about a transfer function between estimated and actual. As it is, when they have an actual reading, they don't include the estimate on the chart. We have no idea how closely they correlate.

Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#57

Post by mason55 »

rconti wrote: post #23
dwighttk wrote: post #21

Earlier quoted context omitted.

Maybe there aren’t many people driving EVs there

Well they're quite common in nordic countries; of course, the population of nordic countries tends to be in the southern latitudes.

Average January low in Oslo is 22 F. In Fargo, ND it’s 0 F. Oslo is at 59 degrees north latitude, Fargo is at 46 degrees north (south of both Paris and Munich)

Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#59

Post by Grim-444 »

Sakos wrote: post #38
crazygringo wrote: post #16

I find it strange that the charts only go down to 20°F, when for example at the moment I write this comment, it's -5°F (-21°C) in Bismarck, North Dakota. And sub-zero Fahrenheit temperatures are pretty common in the winter across the Northeast, especially at night. "Normal" driving conditions extend way below just 20°F.

I figure 20F is just sufficient to prove their thesis (effects of cold on EV cars). I don't think it purports to be an all-encompassing study, especially since there are variables like cabin heating which can have significant effects on range in lower temperatures.

At even colder temps than that EV batteries start having even more problems, for example they become permanently damaged if charged at freezing temps or below, so even more energy has to be used to heat the batteries for the batteries to be able to accept a charge.

Re: Winter & Cold Weather EV Range Loss in 7,000 Cars

#60

Post by Unklejoe »

mrexroad wrote: post #4
JKCalhoun wrote: post #2

Do EV's keep their batteries warm electrically? I know some RV LiPo batteries have integrated heaters to keep the batteries from going below freezing. I suspect that's an acceptable tradeoff in cold climates. Ideally you would keep the battery warm while charging since it's more or less free power when tethered, and thermally insulate the battery enclosure to try to retain that heat as long as possible.

> thermally insulate the battery enclosure to try to retain that heat as long as possible Might pose a problem during heavy discharge with 105F ambient temps?

You could use heat exchangers (coolant) with a thermostat. It would stay closed until the batteries reached a certain temperature then it would dissipate heat through a radiator. Just like a coolant system on an ICE car.
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