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I live in Madison, Wisconsin, US where our winters are cold -- for January and February, the average low is around -10C, with extremes regularly dipping below -20C.

I currently have a 20-year old car. Soon enough, I expect that needed repairs will cost more than the value of the car. When I replace it, I would like to buy an electric vehicle. The problem is, for most of the year I do a majority of my commuting by bicycle, so that I only really use the car during the very cold parts of the year.

However, I've heard that cold weather can reduce electric vehicle range. Is this true? Has the effect been quantified? Does it vary based on model?

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  • I read on a Tesla owners web site one persons' list of recommendations necessary to get good performance ; One that i remember is that the regenerative braking ( to recharge the battery) does not work until the batteries have warmed for a half hour. Dec 4 '19 at 0:51
  • On the Tesla comment, one may now set a "Scheduled Departure Time", which finalizes charging and conditions the car's battery and interior temperatures by the time you need to leave, which should minimize battery issues related to cold weather.
    – pdobb
    Dec 9 '19 at 17:21
  • Anecdotally, I compared my Honda to a co-worker's Tesla last winter (2019). The reduced fuel efficiency of my car in the winter (cold weather, winter tires, short trips) was roughly equal and a little worse than the Tesla (same conditions). My car went from 7.5-8.0 L/100 km to 10 L/100 km. The Telsa lost about 20% battery efficiency. This was for 1 winter in southern Ontario in Canada, which is colder than many places in the world but not Wisconsin in winter. On the plus side, in prairie winters you're plugging your car in anyway. :)
    – FreeText
    Feb 26 '20 at 18:16
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The optimal temperature for a lithium-ion car battery is 20-25°C. When it's cold the battery can store less energy, so the range will go down. Additionally in winter people turn on the car's heater. In a fossil-fuel powered car this means that heat generated by the engine is diverted to the inside of the car. The engine of an electric car however does not generate heat, so when you turn on its heater it will use additional energy from the battery to power a resistance heater thus reducing the range even more.

Tire pressure can also have some influence. Colder temperatures reduces tire pressure which causes more resistance with the road thus also reducing range. Many people check their car's tire pressure once a year at best and when that's in summer they will be driving with too low pressure during winter.

Here in the Netherlands many car review sites list the 'realistic' range of an electric car. This is because the range provided by car manufacturers is way too optimistic as they base their numbers on experiments done in a laboratory. Some review sites provide a pessimistic range (often called winter) and an optimistic range (often called summer). To give an example, this website says the range for a Tesla Model 3 Standard is:

Practical range : 225 - 465 km
  City - Winter    : 300 km     City - Summer    : 465 km
  Highway - Winter : 225 km     Highway - Summer : 295 km
  Average - Winter : 260 km     Average - Summer : 370 km

The site explains (in Dutch, translated here) that they use a model to calculate these numbers and that the model is fine-tuned regularly based on numbers found in practice. For the range in winter they assume -10°C and the use of heating. For summer they assume an ideal temperature of 23°C without using climate control.

I compared the 'Average - Winter' and 'Average - Summer' numbers for several cars and noticed that range in winter is 25-30% less compared to summer. It looks like the reduction is smaller for smaller cars. For the Tesla Model 3 it's 29.7%, for the Peugeot Ion it's 25.0%

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  • The effect of cabin temperature can of course be mitigated by dressing for the conditions, and preheating (or precooling) while plugged in. At they low end of the OP's temperature range this would still reduce the heating power consumption, though not remove it completely.
    – Chris H
    Dec 5 '19 at 7:57
  • Now I wonder about the efficiency of the charge/discharge process vs temperature, rather than the effect of temperature on capacity
    – Chris H
    Dec 5 '19 at 7:58
  • @ChrisH That would probably make a good new question.
    – THelper
    Dec 5 '19 at 8:05
  • I think it would be another useful answer to this one, as efficiency is important for range. I might get time to write it myself.
    – Chris H
    Dec 5 '19 at 9:51
  • I have reason to believe that increased air resistance (air becoming more dense when cold) has a larger effect than tire pressure variations.
    – juhist
    Dec 5 '19 at 20:19
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This totally depends on several things.

Firstly, whether you pre-heat the vehicle. When plugged in, the vehicle may offer the possibility to pre-heat the interior and also the batteries. The interior heating reduces need to convert electricity to heat, and heating the batteries ensures they're at an optimal temperature.

Secondly, whether the vehicle has a heat pump or uses a traditional resistance heater. For some strange reason, one of the most popular EVs, Tesla, uses traditional resistance heaters. Most others use heat pumps.

Cold air is more dense, so air resistance is going to increase. Batteries aren't optimal when cold, but then again all good EVs offer the possibility to heat up the batteries using their energy.

Also, do note that if you store your electric vehicle in very cold uncharged, it destroys the batteries. If you store it charged, it uses some of the charge to maintain a temperature on the batteries to prevent the cold from destroying them. So, don't leave an EV with low charge to very cold temperatures, and don't be surprised that mere storage in cold environments can eat up some of the battery charge.

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  • How much impact does the density of air have? Is this variation on a similar scale to what happens with elevation? I'm skeptical that this would even be measurable compared to other things which affect aerodynamics, such as the amount of bugs on the windshield, or whether the windows are open.
    – LShaver
    Dec 5 '19 at 20:40
  • Air resistance in highway driving is the majority resisting force, i.e. over 50% of energy goes to overcoming air drag. Resistance is proportional to density. Density is inversely proportional to temperature. At 240 Kelvins (-33.15 Celsius) drag is 300/240 times what it is at 300 Kelvins (26.85 Celsius). So the largest resistance force just increased by 25%!
    – juhist
    Dec 5 '19 at 20:55
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If the battery-powered-electric-vehicle charges overnight in a heated garage then I wouldn't expect big problems.

The problem I hear is that air-conditioning use in the summertime can reduce the range of a battery-powered-electric-vehicle.

But it takes less energy to cool a passenger compartment from 90 degrees F to 70 degrees F than it does to heat a passenger compartment from 25 degrees F to 70 degrees F. Combine that situation with the fact that the batteries work better in warm weather than in cold weather and then cold weather is the bigger problem.

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