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After hearing an article on radio 4 about precautions for driving in the current snowy spell my wife asked me how an EV would fare if stuck in a snowdrift miles from anywhere.

The official advice is to drive (your ICE) with at least a half full tank of fuel. Assuming a half full battery, how long would this keep you alive in an EV in extreme conditions? I am not sure how much power the heater alone would consume.

I suppose heated seats may be the answer to keep body core temperature up without draining too much power.

I have a Rex but that wouldn't help because it only cuts in when the car is in motion (I think)
 

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SWMBO got stuck behind an accident on the main road during the last snow storm. She was worried the same, and only turned the car on for brief periods as she had packed extra clothing and a shovel just in case. She was only delayed for 2½ hours, but it was terrible for the range on the GOM - it said she didn't have enough to get home even though the battery was actually more than half full. The next day the range was still low, only showing as 50 miles, but a brisk 50 miles on the motorway later, it was still showing 27 miles.
 

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At a rough guess I'd say you need about 500W continuous to keep you warm inside an EV in winter.
... just warm enough ...

But as you don't know how long it might be then that has to be the way to go. Not much benefit in turning heat on and off from an engineering POV, just run at the lowest fan speed and adjust the temperature according to your needs (Note; this is not the way to drive an EV because low fan and adjusting temperature will lead to misting up, but if you are stuck then it is not an issue.)
 

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SWMBO got stuck behind an accident on the main road during the last snow storm. She was worried the same, and only turned the car on for brief periods as she had packed extra clothing and a shovel just in case. She was only delayed for 2½ hours, but it was terrible for the range on the GOM - it said she didn't have enough to get home even though the battery was actually more than half full. The next day the range was still low, only showing as 50 miles, but a brisk 50 miles on the motorway later, it was still showing 27 miles.
If it happens again, and she has a shovel on board, tell her to hop out and cover the car with a big layer of snow. The exercise will warm her up, and the snow will act as an insulator.

Though you may want to be some distance from her when you proffer this advice...
 

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It's an interesting comparison - EVs don't "idle", so from that point of view it's a lot less inefficient to sit with just the heater running and of course there's no danger of poisoning yourself with CO. But the guess of about 500W to keep yourself from freezing is probably not far off, for an EV with a heat pump, so how long you can last depends massively on battery size and whether or not you have that heat pump.

Teslas with big batteries are not quite as obviously to be preferred as you might think just looking at battery size, due to the lack of a heat pump.

A Leaf 24 isn't ideal due to the small battery, but even so will last a good 10 hours without using much more than a third of a charge - but if you do have to travel it would be worth charging to 100% to add a small safety margin.
 

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At a rough guess I'd say you need about 500W continuous to keep you warm inside an EV in winter. So 5 kWh should last you 10 hours very appx.
Errr... maybe an EV with a heat pump, not one with a resistive heater.

The resistive heater in my Ion draws 5kW on full blast in sub zero temperatures... turning it down to the minimum I can get away with so that I don't freeze I reckon it still averages over 2kW. 500 watts - no chance.
 

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SWMBO got stuck behind an accident on the main road during the last snow storm. She was worried the same, and only turned the car on for brief periods as she had packed extra clothing and a shovel just in case. She was only delayed for 2½ hours, but it was terrible for the range on the GOM - it said she didn't have enough to get home even though the battery was actually more than half full. The next day the range was still low, only showing as 50 miles, but a brisk 50 miles on the motorway later, it was still showing 27 miles.
There is a very logical reason for this.

Let's suppose you had a charge of 20 kWh in the battery when you start. You travel 20 miles at 4 miles per Kw. So you have used 5 kWh, and have 15 kWh left. The GOM is going to suggest that you have 60 miles left ( 15 x 4 miles per Kw).

You then get stuck for 2 hours in the snow, and using some heater, you use maybe 2 Kw, but don't increase your mileage at all. So you have now used 7 Kw to go that 20 miles, which means that the 20 miles have now been at an average of 2.85 miles per Kw. As you now have only 13 kWh left the GOM is likely to suggest that you now have 37 miles left instead of 60 ( 13 x 2.85 miles per Kw). So those 2 hours and 2 Kw used reduces the GOM figure by 23 miles.

The poor old GOM can only go by what you have been doing, and you really have now used 7Kw to go the 20 miles.

Of course in reality if you then carry on, and you actually drive once more at 4 miles per kWh, then the remaining 13 kWh left would get you 52 miles, not the 37 predicted miles.

These are theoretical figures, but maybe give the idea of what is happening.

Don't blame the GOM, it's doing it's best on the information available!

But you can also use the percentage battery figure, to get a better idea.
 

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Heated seats will be your friend if stuck. I may invest in some of those foil blanket things for the car as I have to find something to put in the frunk other than the warning triangle.

If it happens again, and she has a shovel on board, tell her to hop out and cover the car with a big layer of snow. The exercise will warm her up, and the snow will act as an insulator.
Good idea, create an igloo but at what point will you block off the air supply and die of CO poisoning in a sealed car under a layer of snow. ?
 

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The World is a Free and still wild place at times in certain conditions,if you need to venture out into it,be prepared for those conditions to get yourself out of harms way as best as you can.
Snow shovel,warm dry clothing,good strong shoes/boots and provisions.
 

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You missed the full stop. Or even a coherent sentence.

We all know what you mean though.

What should his punishment be?
Full stops and coherent sentences are not formats defined by regulations.

I was trying to be very brief but you seem to have exaggerated it.
 

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Full stops and coherent sentences are not formats defined by regulations.

I was trying to be very brief but you seem to have exaggerated it.
In normal conversation, do you correct people that say ‘I weigh 85 kg’ and point out that they should state their weight in SI units only, so it should be Newtons not a unit of mass?
 

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In normal conversation, do you correct people that say ‘I weigh 85 kg’ and point out that they should state their weight in SI units only, so it should be Newtons not a unit of mass?
Indeed.

They can use whatever measure of force/weight they like, but I do tend to mention kg is a unit of mass and not of weight, and if they don't correct their error then I don't attempt to draw their attention to it again.
 

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42k miles on public charging. Am I an expert yet?
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In normal conversation, do you correct people that say ‘I weigh 85 kg’ and point out that they should state their weight in SI units only, so it should be Newtons not a unit of mass?
I can overlook that - but I cannot bear the people who say "85 kay-gees" when that's total rubbish and entirely meaningless. The correct, and much much much easier, way to say it is "85 kilograms" or even "85 kilos"
 

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As you sit in the snow watching your battery level dropping, you can at least feel happy that with an EV you can keep warm without needing to worry about carbon monoxide poisoning which can be a real danger if you run an ICE while snowed under.
 

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As you sit in the snow watching your battery level dropping, you can at least feel happy that with an EV you can keep warm without needing to worry about carbon monoxide poisoning which can be a real danger if you run an ICE while snowed under.
I imagine that a couple of inches of snow around the car actually insulates you fairly well and reduces the power consumption?
 
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