If you're switching from an internal combustion vehicle to an electric one, the winter may bring some surprises. Range, charging and battery health are all impacted by cold weather, so driving your new EV through the winter months will require some adjustments to your routine as well as some extra planning—especially if you want to go on a longer journey that will require charging along the way.
Keeping the battery pack as close as possible to its optimal temperature is key to getting the most out of your EV in winter, and depending on the car, you have several options to play with to achieve that. Most modern EVs can regulate their battery pack temperature, and you will need to understand how this thermal management works and how to use it best.
Having said all that, cold temperatures may not be as apocalyptic for your EV as you might have heard. Read on to learn more about how to navigate this situation.
The range takes a big hit in cold temperatures, and don’t think that it has to be close to freezing out for your EV’s range to drop by 30 percent or more in some extreme cases. This is caused by increased resistance in the battery cells. This, in turn, affects the entire pack’s efficiency and performance.
The optimal operating temperature range for an EV's lithium-ion battery pack is roughly between 68°F and 113°F (20°C and 45°C). So if the outside temperature drops below about 68°F, your vehicle will use some of its electricity to increase the pack temperature and hold it there. Keep in mind that this is happening even when your EV is turned off, so if you leave it parked outside on a very cold night and don’t plug it in, you will see much more significant range loss compared to leaving it out in milder temperatures.
According to data recently presented by battery health startup Recurrent Auto, which tested a pool of over 10,000 cars comprised of the 18 most popular electric models in the US, EVs retained 70.3 percent of their range in freezing temperatures.
Some vehicles performed much better than average in this respect. For instance, the Audi e-tron lost just 16 percent of its range in winter, making it the best performer of the study. The weakest model from this study was the Volkswagen ID.4, which lost a whopping 46 percent of its range under such conditions.
Lithium-ion batteries of the kind found in most EVs don’t operate as efficiently in cold weather, especially when temperatures dip below freezing. This affects the battery anode’s capacity to capture the lithium ions, which will tend to coat the surface of the anode in a process called coating. Most of this coating goes away through the use of the battery, but it won’t go away completely, and it will accumulate and affect battery performance over time.
You will observe this as a drop in the battery’s capacity, and you will also notice capacity going back up as outside temperatures increase and the lithium coating around the anode is reduced.
An electric car’s battery monitoring system and its thermal management system (usually centered around a heat pump) will be working overtime in freezing conditions to not only give you the maximum possible range but also to prevent damage to the battery. Luckily, modern EVs have evolved to a point where damage to the battery shouldn’t be a concern to you since they are tested and designed to withstand temperature extremes.
Since EV charging speeds are highly dependent on battery pack temperatures, the rate of electron replenishment might slow to a crawl in winter. Matching your EV’s summer charging speed numbers in winter can be difficult, and it will require additional planning.
In many EVs, there is a separate option to tell the car to precondition the battery and prepare it for charging, while in others, the car will do this automatically if you’ve selected a fast charger as your destination. Once you’ve picked out a charger in the nav system, your EV will know that you have the intention of plugging it in, and it will begin to raise battery temperatures in preparation for charging. Definitely check your user manual to see if your car is capable of this, and even watch some YouTube videos to find out how the process works.
If you omit this step and take the vehicle by surprise and plug it into a DC fast charger with a cold battery, you will only be getting a fraction of the advertised charging speed. This may partly explain the Idaho National Laboratory’s report that EVs can take up to three times longer to charge in the cold. The study also discovered that this varied greatly depending on where you lived; EV owners in the northern US (or colder areas with harsher winters, generally speaking) were more likely to experience these longer charging times.
One of the easiest ways you can tell your EV’s battery is not at optimal temperature is by the level of regenerative braking it can provide. Some EVs can put well over 100 kW back into the battery under regen (up to 300 kW for the Rimac Nevera or 290 kW for the Porsche Taycan), but if the battery is cold and it can’t take the power flowing into it from the motors, the vehicle will simply reduce the rate of recuperation until the battery is warm enough to take it.
The level of available regen will increase as you drive, or you can remotely precondition your vehicle so that it’s already up to temperature when you set off. Always leaving your EV plugged in overnight in winter and setting your departure time for the next day will ensure the level of regen you experience won’t vary too much.
If you’re moving from an ICE vehicle to an EV, it may seem counterintuitive that you’re not actually producing as much heat as you drive around normally. In a combustion car, the engine produces a lot of heat—more than enough to heat the cabin—and you don’t really think about its impact on efficiency or range as you do in an EV.
EVs equipped with heat pumps will scavenge some of the waste heat produced by the electric motors and other components, and part of it will be used to heat the cabin. But this often won’t be enough, and they will have to also use their resistance heater to make the cabin toasty on a cold winter’s day.
This is why turning on the heater in an EV, even one with a heat pump, will instantly cause the predicted range to drop. Polestar says that outside temperatures can reduce the range of its EVs by 10 to 12 percent, but if you also use the climate system, that can go up to 41 percent.
One way to get around this issue and stay warm in your EV is to solely rely on the heated seats and steering wheel if they’re available. Keeping the ventilation off will allow the heat pump to use all the heat for the battery pack, keeping it closer to its optimal temperature and giving you the best range.
BMW is equipping its iX flagship electric SUV with the Radiant Heating package, which adds infrared heaters in the armrests, the door panels, and even the lower part of the dashboard. This complements seat and steering wheel heating and encourages you to not use the ventilation system and just rely on radiant heating for warmth during winter driving.
Many EVs have flush-fitting (sometimes powered) door handles that pop out when the vehicle is unlocked. These have the advantage of slightly improving the vehicle’s aero while also making it look cool and modern, but ice buildup can form on top of them, making it difficult to get inside the vehicle.
If the manufacturer doesn’t have a specific technique that you need to apply to get the ice off without causing damage to the bodywork, you may have to get creative and exercise patience. The same can be true for charging port doors, many of which seem poorly designed to deal with the issue of ice buildup.
Another range-sapping part of cold-weather EV driving is the switch from summer to winter tires. Between their different rubber compounds and tread patterns, they produce more rolling resistance, and this will incur a range drop.
You should regularly check the tire pressure in winter, as it can vary depending on outside conditions, and having them underinflated can further penalize efficiency.
Michelin says that rolling resistance can lower an EV’s range by up to 20 percent. It also notes that a 30 percent increase in rolling resistance will increase electricity consumption by between 3 and 5 percent.
Some tire manufacturers like Michelin, Hankook, or Nokian have announced EV-specific winter tires, which aim to strike a better balance between grip and rolling resistance, thus helping electric cars drive further in winter without compromising on safety.
Do you have more questions about winter driving range? Drop them in the comments below.