possible comparisons of EV's in cold.

Frankenblob

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Bjorn Nyland has some good videos on Evs and their range in cold to very cold weather.
May help some who have a couple questions, then again the technology may advance such that these videos become obsolete in 1 year.
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Crissa

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And sometimes they become obsolete because the manufacturers try a new design with a different set of problems (Tesla's Model Y problems in Quebec, for instance.)

-Crissa
 
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Frankenblob

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And sometimes they become obsolete because the manufacturers try a new design with a different set of problems (Tesla's Model Y problems in Quebec, for instance.)

-Crissa
Bjorn Nyland on youtube.
His latest video is:
"Sleeping in 2021 Tesla Model 3 in -26°C"
 

Cyberman

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I was hoping he would share battery percentage after a night like that...
 


ajdelange

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The most interesting observations from the video are that it takes 1.9 kW to keep the cabin at about 20 °C when it is -26 °C outside and that the compressor continues to run even at OAT that low. I can't imagine the COP being very good at that temperature though!

Now picture yourself running down the freeway at 60 mph when it is that cold. If the power for heating stays the same you would be using 1900/60 = 32.7 Wh/mi for heating of cabin and battery. Doubtless infiltration would increase the load but running at 60 also implies a traction power load of about 15 - 20 kW which means losses of .750 = 1.0 kW which are captured and sent back to warm the car. I am trying to dispel the notion that "cold weather cuts your range in half". This data supports my position. It's not the cold weather. It's the stuff on the road that is often present in colder weather.
 
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Frankenblob

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The most interesting observations from the video are that it takes 1.9 kW to keep the cabin at about 20 °C when it is -26 °C outside and that the compressor continues to run even at OAT that low. I can't imagine the COP being very good at that temperature though!

Now picture yourself running down the freeway at 60 mph when it is that cold. If the power for heating stays the same you would be using 1900/60 = 32.7 Wh/mi for heating of cabin and battery. Doubtless infiltration would increase the load but running at 60 also implies a traction power load of about 15 - 20 kW which means losses of .750 = 1.0 kW which are captured and sent back to warm the car. I am trying to dispel the notion that "cold weather cuts your range in half". This data supports my position. It's not the cold weather. It's the stuff on the road that is often present in colder weather.
Also when one is zipping down the road in -26 C at around 60mph the created windchill factor would actually make it seem around -40 C, so its interesting.
 

ajdelange

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Windchill factors are for predicting what happens to flesh - not metal - and so do not apply here. But high air velocity will clearly have an effect of some sort. I tried to cover this under "infiltration" in my last post as I believe that this is how wind will force cold into the car rather than by convection.
 
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Frankenblob

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Windchill factors are for predicting what happens to flesh - not metal - and so do not apply here. But high air velocity will clearly have an effect of some sort. I tried to cover this under "infiltration" in my last post as I believe that this is how wind will force cold into the car rather than by convection.
Oh, I thought windchill also pertained to ANY object that had heat/warmth emanating from it - in so far as "sucking" the heat out/away so as to cool it down fast (hence the faster it cools the more energy/heat is needed to keep it warm) , but - i do understand the flesh aspect and I do see your point.
 


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The most interesting observations from the video are that it takes 1.9 kW to keep the cabin at about 20 °C when it is -26 °C outside and that the compressor continues to run even at OAT that low. I can't imagine the COP being very good at that temperature though!

Now picture yourself running down the freeway at 60 mph when it is that cold. If the power for heating stays the same you would be using 1900/60 = 32.7 Wh/mi for heating of cabin and battery. Doubtless infiltration would increase the load but running at 60 also implies a traction power load of about 15 - 20 kW which means losses of .750 = 1.0 kW which are captured and sent back to warm the car. I am trying to dispel the notion that "cold weather cuts your range in half". This data supports my position. It's not the cold weather. It's the stuff on the road that is often present in colder weather.
It's the cold weather. There are two parts to that, heating the air in the cabin and cold batteries. My friends with Teslas see about a 30% drop in range in winter. The batteries need heat to run efferently, and at cold temps the regen braking conks out. Since heat pumps use about 1/3 the energy, I think the new Teslas will perform a lot better. If you store it in a garage and pre-heat it, it will do lot better. Heat pump+garage storage+pre-heat and I expect to lose around 10-15% range in my future CT. I lose at least that in my gas car in winter, and it has nothing to do with snow or slush on the ground.
 

TheLastStarfighter

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Oh, I thought windchill also pertained to ANY object that had heat/warmth emanating from it - in so far as "sucking" the heat out/away so as to cool it down fast (hence the faster it cools the more energy/heat is needed to keep it warm) , but - i do understand the flesh aspect and I do see your point.
Wind Chill is strictly about human perception of temperature, and as such isn't really scientific. But what you're saying is true, wind (or the speed of a car) will absolutely impact heat loss. Even if no air is getting into the cabin at all, air flowing around the vehicle will significantly increase the heat transfer from in the vehicle to outside. So a parked Model Y will use a lot less power to heat than a moving one. Just like an icecream will melt in minutes if you stick it out the window while driving.
 

Crissa

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If there wasn't a 'wind chill' that worked on nonliving objects, we wouldn't cool things off with fans! It's just not as extreme with objects that aren't subject to evaporative forces.

-Crissa
 

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I believe we are getting bogged down with semantics. When the weather person says the windchill is 30°F that number comes from a specific equation based on heat loss of exposed flesh. I believe it uses averages of body type, skin etc.

More generally, moving air across an object that is at a higher temperature than the air will cool the object faster than if the air was not moving. (why we blow on a spoonful of hot soup before putting it in our mouths) Some (including me) may also call this "windchill".

The word car can mean a specific vehicle that is not a truck. (My dad drives a truck, my mom drives a car). Or it can more generally simply mean any vehicle. (There are 34 cars in the parking lot)

Words can have more than one meaning. Gotta love English.
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