Why Cold and Hot Temperatures Affect EV Range & EV Battery Longevity
In the simplest terms, batteries — including those that power electric vehicles (EVs) — use chemical reactions to create a flow of electrons that, in turn, powers our devices. These reactions occur most optimally within certain temperature ranges.
While this means certain temperatures can affect an EV battery’s range, it also means that temperature can affect the overall performance of your EV on, say, your daily commute. Here, we’ll identify how temperature affects EV performance, and what you can do to help mitigate those effects.
EVs in cold weather
To understand how cold weather affects EVs, it’s actually useful to think about the efficiency of gas-powered vehicles. A gas-powered vehicle converts significantly less fuel into energy — anywhere between 12-30% according to this source — with heat being a principal byproduct. That leftover or “waste” heat produced by fueled vehicles can, in cold temperatures, be used for everything from warming operating parts (such as lubricants in the engine and transmission) to heating the interior and defrosting the windshield.
Meanwhile, a much more efficient electric vehicle may convert (again, an estimate) 80% of battery energy to propulsion. But the EV does not generate that leftover heat, so it needs to use battery energy to warm the battery pack to its ideal operating temperature, in order to heat the cabin, defrost the glass, etc. Of course, if you don’t use the defroster or heater, your EV range won’t decline as much, but who wants to drive in that many layers and use a towel to defrost the windshield?
This means that, ironically, cold temperatures can negatively impact EV range because they would need to use additional energy for heating, whereas gas-powered vehicles can use some of the already dissipating heat for this purpose.
How does cold weather affect EV driving range?
Some experts state that range begins to drop around 40°F, while data from Recurrent set for twelve popular EVs showed range at freezing drops by 16-46%.
To think of it another way, your EV range on a cold highway trip may be 25% less in frigid weather compared to its most optimal range in 80-degree weather.
It’s also worth noting that, depending on the vehicle, range can drop notably even if the vehicle is parked for some time in cold temperatures.
How does cold weather affect EV battery life?
“Life” referred to here is the overall lifetime of the battery pack, not how long it will last on a cold day. In this sense, cold weather does not, in and of itself, negatively affect battery life and longevity. In fact, because the chemical reaction is slower in cold temperatures, there’s less activity-generating heat — heat, which as you’ll see in a moment, isn’t great for overall battery life.
More important than cold temperatures are how and when the battery pack is charged. It should be properly conditioned — prepared to accept faster charging — a process that most modern EVs come equipped to facilitate. For most types of batteries, the maximum charge rate occurs at ambient temperatures of 68-77°F.
While car batteries technically can be charged in sub-freezing conditions, it’s not ideal and will take longer, especially if they’ve not been preconditioned.
How to combat the effects of cold on your EV
Using an EV in cold temperatures can be made easier with a little bit of planning ahead. Beyond parking your EV in a garage and reducing the weight your EV is carrying (both best practices that should be applied to gas-powered vehicles as well), the following measures can help improve battery life in cold weather.
● Whenever possible, precondition the battery and preheat the cabin while it’s connected to a charger. Many EVs connect to an app from which you can set a “departure time,” letting your car know when to preheat automatically.
● Precondition the battery pack for typically 20-30 minutes before DC fast charging. Your EV may lose some range as a result, but the payoff is quicker charging at a higher rate. You can usually do this by setting a navigation destination to a DC fast charger using your in-car onboard navigation or your vehicle brand’s app.
● If your car has them, make use of the heated seat(s) and steering wheel so you can set the cabin temperature lower while remaining comfortable. This practice is analogous to heating a pan in direct contact with a heat source rather than heating the oven to heat the pan. (If you’re curious, many EV onboard displays will tell you what battery use percentage is being allocated to climate control.)
● Keep the vehicle software updated. Doing so can lower battery drain, improve charging performance, and provide you with updated charging station availability.
● If you use a set of winter tires and wheels, mount them to the smallest diameter wheels your car comes with. Winter tires tend to use more energy than “low-rolling resistance” or “eco” tires, but smaller-diameter wheels can help offset these effects.
● Whenever possible, do not park the car for long periods (overnight or more) without a battery charge of 50-60%. This ensures your vehicle will have enough power to warm the battery for better performance before driving and/or power for preconditioning for DC fast charging when it becomes available.
● Try to avoid multi-stop errands. Every time you turn your vehicle off and open a door, the cabin begins cooling. Warming it back up takes battery power. Depending on your vehicle, it may be better to make one single long stop than multiple short ones — or to run your vehicle in a “utility” mode that maintains cabin temperature if you’re out for only a few minutes.
EVs in hot weather
How does hot weather affect EV driving range?
High temperatures will alter EV driving range, though perhaps not to the extent cold weather does (unless you live in south Texas or the desert Southwest). The primary reasons for this echoes that of cold-temperature range drop: climate control of the battery pack.
Your EV’s battery works best within a certain temperature range, and energy is used to control that temperature. As ambient temperatures rise, so does the battery energy needed to control battery pack temperature.
Cabin climate control — primarily air conditioning but also ventilated seats, if you have them — is the other primary power consumer not connected to propulsion. It does, however, normally take less energy to cool a cabin from, say, 95°F to 78°F than it does to warm it from 32°F to 68°F.
There is less data on hot weather’s effects on range than cold extremes. Recurrent’s averaging from 7500 vehicles shows that, compared to its maximum range, an EV loses approximately three percent of its range at 80°F, five percent at 90°F, and — while data at temperatures greater than 100°F is too limited for good averaging — some EVs lose 31% of their range in those temperatures.
Note that some EVs still get their maximum range at more than 80°F, but very few at higher than 85°F.
How does hot weather affect EV battery life?
Beyond certain temperatures, the rate of chemical reaction inside a battery increases. When an EV is recharged in high temperatures and above the ideal state of charge range of 20% - 80%, the degradation process speeds up.
Occasionally, charging your EV in high temperatures won’t have significant effects, but summer commuting to a daytime charger in Phoenix will result in shorter battery life compared to if the battery were charged at home overnight.
How to combat the effects of heat on your EV
As with cold temperature best practices, always try to park your car in a garage overnight when temperatures rise. When you know you’ll be driving in extreme heat, reducing the weight of cargo carried, minimizing high-speed driving, and keeping your tires properly inflated can add miles to your range. Beyond that:
● Park in the shade (natural or man-made) whenever possible and crack your windows and/or moonroof if conditions and weather allow.
● If laws allow it where you live, consider tinting the rear and rear-side windows — if they aren’t already.
● If your vehicle has them, use seat ventilators to maintain comfort even in a warmer cabin.
● When possible, precool the car while it’s plugged in, not before. While the car is plugged into an L2 or L3 charger, it can draw the power there to cool the cabin and, if needed, precondition the battery. If the car is not plugged in, it pulls battery power.
● Use onboard data to find the battery state of charge at which your vehicle optimally operates.
The Mazda CX-70 PHEV and CX-90 PHEV
If you’re concerned about how a cold spell or heat wave might affect your EV’s range, consider a plug-in hybrid like the Mazda CX-70 PHEV or the CX-90 PHEV. Both models combine an electric motor that provides electric-only driving that’s perfect for short commutes and around town with a traditional gasoline-powered engine that’s used for longer journeys or extra power when the EV battery is depleted.
Wherever the road takes you, there’s a Mazda crossover SUV that can suit your budget and lifestyle. Shop Mazda crossover SUVs online, schedule a test drive, or simply visit a Mazda Dealer near you today.
This article is intended for general informational purposes only and is based on the latest competitive information available at the time of posting. Information herein is subject to change without notice and without Mazda incurring any obligations. Please review a variety of resources prior to making a purchasing decision. Visit Resource Center for more articles.