What They Don’t Tell You About Driving Electric Cars In A Heatwave

May 13, 2024

Learn the untold truths of driving electric cars in scorching heatwaves. Stay informed for a smooth EV driving experience.

The history of electric cars dates back to the 1830s when prototypes first emerged. However, it wasn't until Tesla introduced the Roadster in 2004 that electric cars gained significant recognition. The Roadster was groundbreaking as it became the first highway-worthy electric vehicle powered by a lithium-ion battery. Since then, the electric vehicle industry has made a lot of progress.

Leading manufacturers like Tesla are working hard to create electric cars that compete with traditional Internal Combustion Engine vehicles in terms of performance, range, and reliability. These modern EVs are impressive and offer a sustainable and eco-friendly alternative for transportation.

However, according to a study by Recurrent, recent issues have surfaced about what happens when driving electric cars during heat waves. As a result, it becomes important to understand that extreme temperatures can impact the performance of any vehicle, and electric cars are no exception. The high temperatures can affect battery efficiency and overall driving range.

With that in mind, here's everything you need to know about electric vehicles and their problem with heat waves.

Related: These 10 EVs Deliver The Best Range For Your Buck

One of the most important questions while purchasing an EV is its range. While we recently discovered that cold weather reduces EV range, hot weather is equally bad. Recently, a Seattle-based EV battery and range analytics company, Recurrent, conducted a study that sheds light on a significant concern for electric vehicle owners during heatwaves.

With temperatures steadily rising, particularly in the Southern and Western parts of the US, the research reveals a notable decline in the driving range of some popular EV models. According to their findings, these electric cars experience a decline in driving range, highlighting a major problem among EV owners.

During the test, plenty of vehicles experienced prominent range declines with rising temperatures. Some of the car's range plundered up to 31 percent when the temperature rose above 100 degrees Fahrenheit.

While calculating the average temperatures, Recurrent tracked 17,000 electric vehicles. The dataset includes 65 models of EVs along with plug-in hybrids, including popular cars like Tesla Model 3, Model Y, Model S, Model X, Hyundai Kona, Ford F-150 Lighting, and Mustang Mach-E.

While Recurrent refused to disclose the names of the worst-performing EVs, it is seen that Tesla performed the best. However, Tesla's real-world range notably differed from the EPA estimates, indicating a wide gap between the figures. While Tesla's one of the biggest problems has always been the real-world range, the test further clarifies the issue.

Besides, it is important to note that the tested vehicles performed well, with an average decline of 2.8 percent at 80 degrees Fahrenheit and 5 percent at 90 degrees Fahrenheit. Another important revelation found at the test demonstrates that Tesla vehicles get only 60 percent of their EPA range under normal conditions. Nevertheless, there are some ways to improve your Tesla's range.

Tesla has done a lot of R&D for making their industry-leading climate control system that is present across all newer Tesla models. Teslas come with heat pumps that manage both heating and cooling instead of the traditional refrigerant-based cooling and resistance heaters that are found across most cars. Tesla cars also feature cabin overheat protection that prevents them from getting too hot.

The air conditioner used in a Tesla is a variable-speed unit. As a result, it depends on your cooling needs. Sometimes, it can use as little as 1 kW or can go as much as 6 kW. Nevertheless, when the AC is working to keep your cabin cool at a reasonable temperature of 90 degrees, you can expect a moderate range loss.

Teslas also have dog mode, which runs the AC as well to keep your dog cool and lets spectators know via the screen what the current temperature of the car is.

Related: 10 Things To Know About The Tesla Roadster

The Mustang Mach-E comes equipped with an auto-cool feature that adjusts the fan speed in the cabin to reach the desired temperature. However, this climate control is a lot more confusing than it is assumed, according to some Mach-E drivers. Another notable feature of Mach-E is that the fan speed will automatically decrease and quiet down if you take a call or give a voice command.

Mach-E owners told Recurrent that the aircon needs to be adjusted to save the battery and maintain the range. At the same time, the owner also says that when driving, it is easier to keep the car and driver cool than when being parked.

From the data shared, it is seen that Mach-E surpasses the estimations shared by EPA in terms of range when the temperature is around 80 degrees Fahrenheit. But, the range starts to take a dip when the temperature crosses the 95 degrees mark.

While the projected range loss is only 1 percent when the outside temperature is close to 90 degrees Fahrenheit, it increases to 16 percent when the outside temperature reaches close to 100 degrees Fahrenheit.

Earlier, Ford F-150 Lightning drivers informed Recurrent about preconditioning issues, but Ford has incorporated two different settings to pre-cool your car. First, there's Departure Time, which can be set by using the mobile application or from your car. This setting cools the cabin when the car is plugged in. The next one is Remote Start which warms or cools the cabin before you get inside.

When compared with Mustang Mach-E, the F-150 follows the same footsteps. The F-150 Lightning's range starts to drop when the temperature reaches 85 degrees Fahrenheit. However, because the car is new, more data is needed to reach some concrete observations.

The data provided by Recurrent shows that compared to the maximum range claimed by the Ford F-150 Lightning, the range loss is 1 percent at 90 degrees Fahrenheit and keeps on reducing till the outside temperature reaches 100 degrees.

Related: The 10 Fastest-Charging Electric Cars

According to the International Energy Agency, EVs sold in the USA have an average range of 217 Miles on a single charge. Although with the steady growth, EVs still fall short when compared to ICE cars.

According to Graig Less, technical director at the University of Michigan Battery Lab, once the temperature is above 104 degrees Fahrenheit, the passive emission layer on the anode breaks down and consumes the liquid electrolyte that shortens the lifetime of your battery.

However, he also thinks 104 degrees is not common in everyday driving conditions. In addition, EVs have a cooling system installed on their battery packs that act as passive cooling. So this protects the battery at higher temperatures. But, at the same time, also uses electricity to work, thus reducing range.

Air Conditioners and Resistance Heaters are both used to regulate the cabin temperature of an EV. While the aircon uses a compressor to cool the air inside the cabin, the heaters work by passing an electric current through the resistive element that converts electrical energy into heat. They efficiently warm the cabin, but at the same time consume a lot of energy.

In cold weather, EVs experience a decrease in energy output, and with the use of resistance heaters, the battery drains much faster. On the other hand, in summer, the outside temperature is slightly higher than the ideal cabin temperature, so the air conditioner has to cool the cabin by a small temperature difference, which does not affect the range much.

But when the outside temperature rises above 100 degrees Fahrenheit, the EV range starts dropping because the AC requires much more effort to cool the air inside of the cabin.

Sources: RecurrentAuto, AutoNews, and IEA

Anubhav is a passionate writer who also enjoys cars and technology. With a keen eye for detail and a deep understanding of cars, he effortlessly weaves his expertise into engaging narratives.