Do Electric Cars Work in Cold Weather? Get the Facts…

, senior engineer, Clean Vehicles | February 16, 2016, 10:30 am EST
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In short, yes. All cars (both gasoline and electric) have lower fuel efficiencies at colder temperatures, decreasing how far the vehicle can travel without refueling. However, because some electric vehicles (EVs) have a lower range than the typical gasoline car, these efficiency losses can be an important consideration when choosing an EV in places that have cold winters. Still, today’s EV’s work just fine in cold climates, and new models will be even better.

An EV on the slopes of Mt. Hood in Oregon. (Source Oregon Department of Transportation flickr/oregondot)

An EV on the slopes of Mt. Hood in Oregon. (Source Oregon Department of Transportation flickr/oregondot)

Gasoline vehicles and electric vehicles both lose in cold weather

In cold weather, all cars get less efficient. For gasoline-powered cars, factors like cold engine oil and increased idling can reduce fuel economy in freezing conditions by 20% or more. Overall, electric cars are more efficient than gasoline cars because an electric motor is much more efficient in turning stored electricity into motion than an internal combustion engine is in converting the chemical energy of gasoline to mechanical energy.

You can see (or feel) this inefficiency when considering the energy lost in the form of heat that leaves a gasoline car through the tailpipe and radiator. That heat is energy from the gasoline that is wasted. About 60% of the energy from gasoline is turned into heat, while only about 20% goes to drive the wheels. However, when temperatures dip, this “waste” heat is used to warm the cabin.

A battery electric car lacks a wasteful (but warm) engine, so an electric heating system (either a resistive heater or heat pump) is needed to keep the inside climate toasty on a chilly day. This electricity for heating will come from the same battery that’s used to power the electric drivetrain, so the effective range will drop in cold weather (assuming the driver chooses to use the heater).

Not all of the loss in range is due to the climate control system. Batteries also have lower performance as the temperature dips due to the impact of the temperature on mobility of electrons through the battery. To keep performance and reduce accelerated aging of the batteries, many EVs have a thermal management system that keeps the battery warmed (or cooled in hot temps) to an optimum temperature range. Warming the battery pack takes power that reduces range. Heating the cabin and battery combined can increase the auxiliary power load on an EV like the Nissan LEAF from below 1 kW to almost 3kW as the temp goes from 68 ºF to 10 ºF.

”Nissan

There are ways to reduce the impact of cold temperatures on the performance and range of EVs. One is to heat the cabin and/or battery before unplugging the car. This “preconditioning” of the EV can even be done by a smartphone or watch app on some cars. It’s similar to the use of engine block heaters and remote start systems used on gasoline cars (though without the exhaust of an idling engine). Grid electricity is used by the EV to warm the battery and interior, so that more of the car’s stored electricity can go to driving the wheels.

Electric vehicles are also getting better at cold temperature performance. For example, using high efficiency heat pumps can provide cabin heating with much less drain on the battery than a resistive heater. Other design improvements can help such as using heat from the electric motor and power control electronics to heat the battery and/or the vehicle cabin. These types of improvements have typically been found in EVs that were designed from the start to use an electric drivetrain, so we should see these more efficient features become more common as more manufacturers build “EV-only” models like the Chevy Bolt and BMW i3.

People are buying, and loving, EVs in cold places

So how do EVs work in the real world for people in cold climes? The EV fleet management company Fleet Carma has tracked trips in the Nissan LEAF in Canada and the U.S. and found that overall range drops from close to 80 miles in shirtsleeve weather to 50-60 miles when driven in below freezing conditions.

This is a noticeable drop, but still leaves enough range for many drivers. For example, our survey of U.S. drivers found that 54% reported daily driving of less than 40 miles and 69% drive less than 60 miles on the average day. For a longer range EV, like the Tesla Model S or the upcoming Chevy Bolt, the impact of cold weather is likely to be less of an issue. These cars have more total range available, so any loss of range will impact driving utility less and offer drivers ample battery capacity to run both the motor and heaters for extended drives. For example, Telsa reports that their Model S 70D model loses about 19% range when driving in 0 degree Fahrenheit weather with the heater on, reducing the range to 195 miles.

 

Nissan LEAF average range as a function temperature. Data from Fleet Carma via “Effects of Regional Temperature on Electric Vehicle Efficiency, Range, and Emissions in the United States”

Nissan LEAF average range as a function temperature. Data from Fleet Carma via “Effects of Regional Temperature on Electric Vehicle Efficiency, Range, and Emissions in the United States”

Tesla Model S 70D highway (65mph) range as a function temperature. Because of its larger battery pack and more efficient thermal management system, the Tesla retains nearly 200 miles of range at 0 degrees Fahrenheit. Data as reported on Tesla Motors website.

Tesla Model S 70D highway (65mph) range as a function temperature. Because of its larger battery pack and more efficient thermal management system, the Tesla retains nearly 200 miles of range at 0 degrees Fahrenheit. Data as reported on Tesla Motors website.

If they work in Norway, EVs can handle our winters

To see if EVs work in cold weather, one can look at the example of Norway. Norway’s generous incentives for EVs has made electric vehicles popular in this Nordic country. Over 70,000 EVs have been sold in Norway, and EVs made up over 20% of all new cars sold in the first 9 months of 2015. Subsidies are a major reason for these high EV sales rates, but drivers wouldn’t be picking these cars if they didn’t work for their driving needs. Not only are Norwegians picking EVs, but also many of them are choosing shorter range EVs from Nissan and Volkswagen, despite the sub-freezing average winter temperatures. EVs are also working closer to home in colder climates like Canada and Vermont.

One Chevy dealer in Quebec has even moved his dealership to selling mostly Chevy Volt plug-in hybrids.

EV performance is impacted by cold weather, but an electric vehicle can be a good choice for many Americans, even those in the northern reaches of the country. And in the Northwest and Northeast states EV drivers can access some of the cleanest electricity in the country, greatly reducing emissions from driving (use our EV tool to calculate emissions in your local area). Affordable longer range EVs will make cold weather even less of an issue—but even today’s EVs are working all-year round in every state in the nation.

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  • Jean Potuchek

    I just checked the average winter temperatures in Oslo, Norway and they are *much* warmer than winter temperatures at my home in Maine. I’d be interested in learning more about experiences with EVs in Vermont and Quebec, which seem more relevant to my circumstances.

    • neroden

      Well, I drive a Model S85 in upstate NY, and I’ve driven it on a road trip to Michigan, through Canada. Temperatures have dropped as low as -20F.

      The absolute worst case mileage I’ve *ever* seen was when I lost 33% of my range, bringing my range down to about 177 miles. So you can use that as a worst-case scenario. This is very very rare.