The Truth About EVs In Cold Weather And How To Deal With It

MAR 19 2019 BY EVANNEX 22

COLD WEATHER’S IMPACT ON ELECTRIC VEHICLES, AND HOW TO COMBAT IT

Guest post: Blane Erwin, Current Automotive

Since winter is making its last strike at the Midwest and Northeast this week, it’s a good time to take a look at how cold weather affects electric vehicles. In particular, electric vehicle shoppers are concerned about their range decreasing. This February, AAA released a report detailing just that.

*This article comes to us courtesy of EVANNEX (which also makes aftermarket Tesla accessories). Posted by Matt Pressman. The opinions expressed in these articles are not necessarily our own at InsideEVs.

Image: Current Automotive

THE AAA STUDY

AAA tested five battery electric vehicle models that all bring at least 100 miles of range on a full charge: a 2018 BMW i3, 2018 Chevy Bolt, 2018 Nissan Leaf, 2017 Tesla Model S 75D, 2017 Volkswagen e-Golf. Each of the five cars were fully charged, then run on a dynamometer (a treadmill for cars) six times in different conditions until their batteries were empty. The cars were run twice at three different temperatures: 20 degrees Fahrenheit, 75 degrees Fahrenheit, and 95 degrees Fahrenheit. One run at each temperature was done using climate control, one run was done without.

Compared to running at 75 degrees, the cars experienced the following:

-At 20 degrees: A 12 percent decrease without heat, and a 41 percent decrease with heat.

-At 95 degrees: A 4 percent decrease without air conditioning, and a 17 percent decrease with air conditioning.

WHY?

All batteries, whether they’re in cars, cell phones, or laptops, have an ideal operating temperature where they can deliver the most energy without losing it. This is why your cell phone doesn’t last as long if you’re using it while it’s cold outside, or why it may automatically shut down if it begins to overheat.

Specifically, cold temperatures slow down chemical reactions within a battery, reducing power output and threatening battery life. Electric vehicles have been designed to protect themselves with onboard heaters to warm the battery. Electric vehicles carry a limited supply of electricity onboard with them, so the energy used to heat the battery isn’t being used to turn the wheels, reducing the total available range.

Road conditions can also make a difference. Winter brings wet and snowy roads, which increases the amount of resistance a car has to overcome to get moving. Therefore, the car has to use more electricity to get up to speed compared to a dry road, resulting in less range.

Source: Current Automotive

Driving conditions aside, the biggest impact on range is the use of climate control. It takes a lot of energy to heat or cool an environment. For example, think of your home. When you’re cranking the air conditioning or heat at home during the hottest and coldest months of the year, your electricity and gas bills are bound to be much higher. That’s because you’re using so much more energy to maintain a comfortable environment at home.

While a car may be smaller, it still takes a lot of energy to heat or cool the cabin. The inefficiency of internal combustion engines means they actually have an advantage in this area. Engines produce tons of heat as a waste byproduct of their operation. During the winter, some of that heat isn’t wasted, it’s used to heat up the cabin instead.

Because electric cars are so much more efficient, they only produce a fraction of the heat an internal combustion engine does. While that reduces your running costs, it means they have to draw electricity from the battery directly to warm things up. Again, any electricity being drawn from the battery that isn’t being used to turn the wheels will reduce the total range available from a full charge.

HOW TO HANDLE IT?

The good news is that most new electric vehicles are hitting the market with over 200 miles of range. A 40 percent reduction of that leaves a driver with 120 miles, which should still be enough to cover the vast majority commutes. As long as there is enough range to make the return trip with the ability to charge back up every night, there’s no reason to fret about winter range reduction.

The impact of cold weather range reduction can also be mitigated by preconditioning the car at home before leaving in the morning. Preconditioning is the practice of starting the car and getting the climate control running while it’s still plugged in. That way, the cabin can reach a comfortable temperature while it’s still getting energy from the power grid. Then, the car won’t have to use so much electricity to keep its driver happy on the road, and the battery will be at its ideal operating temperature, maximizing range.

Image: Current Automotive

Plug-in hybrid owners should be aware that their already limited all-electric range will be impacted in the same way. Losing nearly 20 miles from a Honda Clarity Plug-in Hybrid’s 47-mile all-electric range is more noticeable. If the car can no longer complete the trip on electricity only, gas station visits will become a little more frequent though still not as regular as a conventional car.

TESLA SUPERCHARGING V3

Cold temperatures also reduce charging speed. While it may not be a concern for a nightly charge at home, it does have a noticeable impact at fast-charging stations. Any extra delay at a place where drivers are meant to get in, charge, and get out as fast as possible is noticeable.

Tesla’s Supercharging V3 update will heat up the car’s battery while its driver is en route to a Supercharger. The battery will be at the optimal temperature on arrival, so it charges at the maximum possible speed.

THE POSITIVE SIDE

All cars experience a range reduction in cold weather, even conventional gas-burners. According to the U.S. Department of Energy, which runs https://www.fueleconomy.gov, they get about 12 percent worse fuel economy at 20 degrees Fahrenheit. That’s the same reduction in range as an electric car at the same temperature. Short trips of less than four miles can result in a 22 percent reduction in fuel economy.

While electric vehicles may lose some range during the winter, they actually have an advantage over conventional internal combustion engines in winter reliability. “Issues unique to ICE [internal combustion engine] vehicles include increased drivetrain due to increased viscosity of driveline fluids before the vehicle reaches operating temperature, and winter grades of gasoline which can have slightly lower energy content than summer blends,” said AAA Spokesperson Ellen Edmonds.

There are so many moving parts and fluids in an internal combustion engine, and many are affected by cold weather. This article by Car and Driver outlines a few of them: moisture can freeze in the fuel lines, serpentine belts can become brittle and break, thick oil accelerates wear-and-tear on other engine components, and the 12-volt battery can die, leaving the driver stranded.

With an electric car, you don’t have to worry about any of that.

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*Source: Current Automotive; Editor’s Note: Current Automotive is the first-ever U.S. car retailer focused exclusively on used electric cars launched by two former Tesla employees.

*Editor’s Note: EVANNEX, which also sells aftermarket gear for Teslas, has kindly allowed us to share some of its content with our readers, free of charge. Our thanks go out to EVANNEX. Check out the site here.

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22 Comments on "The Truth About EVs In Cold Weather And How To Deal With It"

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So, when it’s all said & done it’s “six of one” half dozen of the other…. 🙁 *** 🙂

Good article from Now Evannex( former Tesla Pravada)

I especially like the comment that ev’s don’t have 12v batteries, so they can’t fail in cold weather. Guess the writer doesn’t really understand how current ev’s are built. .

I don’t see the 12V lead acide battery going away anytime soon. It’s just too simple of a solution versus replacing it with something else. You could tap 12V from the main HV battery, but that’s kind of a solution looking for a problem. Some people suggest using a 12V lithum ion battery, but that’s just increases cost with the only real benefit is it being smaller/lighter.

Some EVs don’t have a standard 12 V Lead Acid battery. I am pretty sure Hyundai/Kia ditched them completely from their electrified vehicles. They use a Li-ion embedded in the main pack to activate HV system.
https://www.caranddriver.com/news/a15341302/how-the-hyundai-ioniq-ditched-its-traditional-12v-lead-acid-starter-battery/

Well, the GM products still have a 12 volt lead-acid agm battery even though they may have an ICE which is started off the high-voltage battery. They still need the 12 volt battery to enable the computers and pumps.

One brand of EV’s in the cold goes through 12 volt batteries in the very cold once every 4 months. So its not a trivial problem – although I suspect this does not apply to the latest models.

It’s important to dispel the silly notion that cold weather somehow makes energy “disappear” from batteries. It doesn’t. It takes energy to warm any car, but you won’t notice that as much when you are already throwing away as heat 80% of the energy you are using to move a combustion vehicle. If reduced range in cold weather is a problem, consider installing a fossil fueled “parking heater” to create a different kind of hybrid that provides plenty of heat without the complexity of an internal combustion engine.

Wabasto and others build little diesel fired 12V water heaters, this may be a solution in Alaska. A diesel burning EV, that’s just wrong but maybe practical.

Or heat it up while still plugged in

Call me silly, .. but I’d say: “Battery capacity does ‘disappear’ in cold weather”:

“Cold temperature increases the internal resistance and lowers the capacity.”
https://batteryuniversity.com/learn/article/discharging_at_high_and_low_temperatures

— a rubber bucket of electrons

Hey Silly, the power doesn’t “disappear”. Resistance is heat production. This is work. So the energy either goes to a resistive battery heater to warm it up or the battery’s own resistance heats it up. Either way, the energy does not just disappear.

This (and the other couple of similar articles over the last couple of months) are quite enlightening and really separate out the issues, rather than just “they lose 40%”.

Hopefully the next generation of EV’s will come out with something that properly mitigates the main issue – cabin temperatures. Current generation heat pumps are just not good enough when it gets cold enough to worry about (below freezing) and solutions like not using cabin heat are not feasible for most consumers.

Whether the consumer solution does become a separate liquid fueled cabin heater, or something else, I don’t know, but surely a lot of companies are looking at this.

You can already warm up the car while plugged in.

This is primarily why many EVs come with heated seats as standard equipment. It’s more efficient than warming the cabin air.

But not very comfortable when it is cold in the cabin.

Article seems lacking in information. It’s unlikely that all the cars experienced the same reduction in available range. I would think climate controls in particular could be different, for example if seat heating is being primarily used for 1 passenger, if the car is equipped with a more optimal heat pump, what temperatures the climate controls are set for, etc. I wonder if the AAA study lacks these details as well? I did find it interesting that ICEs and EVs experience about the same reduction in range for colder temperatures, when climate controls are not used.

True! It will vary with battery capacity and kind of riding, long highway drive in sunshine only or just multiple stop and go at night errand.
Better insulation and air circulation might also differ.
Bottom line, it won’t be all the same.

It might be a good idea then, to spec the color of an EV in black in colder climates as opposed to white (good for warmer climates however). The black color will draw in more heat allowing a small degree of better efficiency.

Unfortunately colder climates regularly have 30+ degree (centigrade) summers, so black cars would need more AC for several months of the year.

Lower temperature and lower humidity also affect air density. So the aerodynamic drag does also increase regardless of the propulsion system.
And winter tires typicaly have higher rolling resistance than summer tires.

Good article “but” why does an article about a test of 5 cars, none of them a Model 3 show only Model 3 pictures?

Your article makes a distinction with gas vehicle mileage reduction between short trips and long trips. You need to make the same distinction with EVs !! I took several long freeway trips in my Model 3 this winter, with heat on – and documented range reductions between 18% and 25%.

Long trips are when you need your maximum battery range – not short trips. So all the recent reporting on this issue has been fundamentally flawed.

It’s all about the temperature of the battery. On long trips, the battery warms up and gets back to near normal performance with time. Supercharging also does a great job of warming the battery. In fact, my future long-range winter trips will start with visiting a nearby Supercharger. I’ll let you know if this helps next winter.