我们都知道电动车在寒冷天气续航里程会下降，而总部位于西雅图的 Recurrent 公司近日发布研究报告，指出过热也会大幅减少电动汽车的续航里程。
报告称电动汽车在 38°C 高温环境下，续航里程平均下降 31%。
Recurrent 公司每年都会研究和测试数千辆汽车，用于分析电池与其续航里程之间的关系。
Recurrent 公司在报告中并未提及具体车型，不过他表示：
在 80 华氏（26.6 摄氏度）环境下，平均续航里程下降了 2.8%；
在 90 华氏（32.2 摄氏度）环境下，平均续航里程下降了 5%；
温度上升到 100 华氏（38 摄氏度）后，平均续航里程下降了 31%。
密歇根大学电池实验室的 Greg Less 表示，当电动汽车处于高于 104 华氏的高温状态下，会击穿电池阳极上的被动发射层（passive emission layer），消耗电解液，缩短续航里程。
以下为报告原文：
Turning off the air conditioning (A/C) makes a combustion engine car more efficient – maybe you’ve even tried this when running low on gasoline. The A/C consumes energy, which requires fuel, and that depletes the gas tank.
So, what about in an electric car?
One of the biggest questions that people have about EVs is about their range variance. We know that cold weather reduces EV range. Temp drops affect some models more than others, but no electric car is immune. For warm weather, the data could be more confusing so we analyzed battery readings from 7,500 vehicles to answer the summer range question and underlying concerns.
The tl;dr: go ahead and use your air conditioner. A/C has much less of a negative impact on EV range than a resistance heater, and range does not really begin to dip until at least 85 degrees. The difference between ideal cabin temperature and outside temperature is usually smaller in the summer than in the winter. In the summer, you may want to change the inside temperature 20 or 25 degrees, but in the winter, you may be looking at a temperature change of more than 50 degrees!
And, much like in the winter, you can save your range for the road by pre-cooling your car while it’s still plugged in. If you’re not starting your trip from home, things like sun shades or parking in the shade can also really help.
Overall, cooling your EV’s cabin will be less range intensive than heating it.
Why is EV cooling different from ICE cooling?
What’s the same? Basic air conditioner maintenance. While electric air conditioners are simpler systems than mechanical ones, you should still check your air filters and hoses regularly.
Findings: On average, we found that, compared to the maximum range that our vehicles get:
Note that the range loss at 100 degrees is based on extremely limited data, and we will update it when we have more confidence in the value
The map below uses reported national high temperatures from July 4, 2023.
Chevrolet Bolt EV
The Chevrolet Bolt has become famous at Recurrent Headquarters for having the most accurate dashboard range out of all the vehicles we have examined. It hits about 100% of its EPA range in the low-to-mid 70s, and range slowly starts to decrease above 80 degrees.
In general, the Bolt’s AC uses about 1 kW to cool the car. There is a very handy “energy” screen that shows you just how much of the Bolt’s battery goes to driving, as opposed to climate control and battery thermal management. Anecdotally, most drivers find that the Bolt’s AC increases energy consumption 2-4% to keep temperatures in the mid-70s, and up to 11% for a cooler car. One Floridian reported that on short drives in almost 100 degree weather, the Bolt’s consumption screen showed up to 20% for climate, but that is an upper bound. Short trips will be more energy intensive since cooling a hot cabin takes more energy than maintaining an even temperature.
Other cautions from Bolt owners are:
The best option? Pre-cool your Bolt before getting in it for a comfortable ride from the first second, plus less energy drawn from the battery. This can be done in the MyChevy app while the Bolt is still charging.
If you want to leave your Bolt running with the AC on, like if you’re running into a store and want to leave groceries in the car, it will idle with climate control. Drivers say it will shut off after an hour, rumoredly two hours if the seatbelt is connected. You also have the option of remote-starting your car, which will give you 20 minutes of cool-down time before you get back to it.
The chart below shows observed temperature variation for a selection of our Chevrolet Bolt vehicles using 13 vehicles and 950 data points.
Using our range models, we estimate that compared to the maximum range that a Bolt can get, the range loss at 90 degrees is 9%.
Hyundai Kona EV
Across the spectrum of warm weather, the Hyundai Kona EV exceeds its EPA estimated range for all the vehicles we observed - by as much as 30%. We don’t yet have enough hot-weather data to say for sure when the Kona’s range begins to fall, but the preliminary data below shows that it may start to trend down around 93 degrees.
The Hyundai Kona EV can be pre-cooled in two ways:
The chart below shows observed temperature variation for a selection of our Hyundai Kona vehicles using 8 vehicles and 444 data points. The bumpiness of this graph will improve with more hot weather data.
Using our range models, we estimate that compared to the maximum range that a Kona can get, the range loss at 90 degrees is 5%.
Mustang Mach-E
The Mach-E comes with an “auto” cool setting that should theoretically adjust the fan speed in the cabin to quickly reach the desired temperature, but in practice, Mach-E drivers have a lot of questions about their climate control and some worry that it’s more complicated than it needs to be. One nice feature is that the fan speed will decrease and quiet down if you take a call or try to give a voice command.
One driver located in the Southwest reported that once the temperature gets above 113 degrees, the air conditioner has to be diverted to keep the battery in a safe range. However, the same driver explains that when driving, as opposed to parked, it’s easier to keep both car and driver cold.
In terms of the pre-cooling a Mach-E, or leaving it with AC while the car isn’t running,
From our data, the Mustang Mach-E seems to outperform its EPA estimate when temperatures get above the mid-80s. Like the Kona EV, it seems like the Mustang Mach-E’s range begins to dip around 93-95 degrees. We project a range loss of 16% once the thermometers hit 100 degrees, but more summer data is needed to verify.
The chart below shows observed temperature variation for a selection of our Mustang Mach-E vehicles using 20 vehicles and 1210 data points.
Using our range models, we estimate that compared to the maximum range that a Mach-E can get, the range loss at 90 degrees is 1%.
Nissan LEAF
Most LEAF drivers report that their air conditioner can use up to 3.5 kW of power to initially cool the car, while it takes only 1-1.5 kW to maintain a cool temperature. Luckily, you can precool a LEAF while it’s hooked up to a power source in order to do the bulk of the cooling without impacting range. With earlier model years, remote pre-cool is limited to SV and SL trims.
In terms of leaving the air conditioning on in your LEAF, it is necessary to keep the car on and in park. But, if you’re running errands or leaving someone in the car, you can still take your key with you and lock the doors. The car will not be able to start or drive off without the key.
Note that the LEAF begins to see a decline in range at lower temperatures than many of its competitors - around 75 degrees, the observed range tapers off.
The chart below shows observed temperature variation for a selection of our Nissan LEAF vehicles using 49 vehicles and 4178 data points.
Using our range models, we estimate that compared to the maximum range that a LEAF can get, the range loss at 90 degrees is 22%.
Ford F-150 Lightning
Although some early Lightning drivers reported issues with preconditioning, Ford has included two separate settings that can pre-cool your car. Departure Time, which can be set via the app or in the car, will precondition the battery and cool the cabin when the truck is plugged in. If you’re not plugged in, departure time will only cool the cabin. Remote Start is another app-based option to warm or cool the cabin prior to getting in.
In terms of leaving the truck running with AC on, the F-150 seems to follow the example set by the Mustang Mach-E. The air conditioning will shut down after 30 minutes of the car being left in park, although this timer can be disabled through Settings –> Vehicle –> Vehicle Power Down Timer. You’ll have to disable this timer every time you want to leave the car idling.
The F-150 Lightning starts to see a slight range drop off at 85 degrees, however it is new enough that more data is needed to smooth out the observed range at high temperatures.
The chart below shows observed temperature variation for a selection of our F-150 Lightning vehicles using 7 vehicles and 615 data points.
Using our range models, we estimate that compared to the maximum range that a F-150 Lightning can get, the range loss at 90 degrees is 1%.
The Teslas: Model 3, Model Y, Model S, Model X
The case of Tesla is unique. Ask any Tesla driver, and they will tell you they’ve long known that the constant, consistent dashboard range seen on their cars does not reflect the very real changes in range they may experience when it’s very cold – or very hot. In fact, the dashboard numbers don’t seem to reflect drive styles, terrain… or much else. However, Recurrent recently released Tesla Real Range, which is the first publicly available data to reflect the temperature dependence of Tesla’s range. Unsurprisingly, Tesla range does vary with temperature, like all lithium-ion powered EVs.
All EV drivers love the instant cold of electric air conditioning and Teslas are no exception. In fact, Tesla has sunk a lot of R+D into industry-leading climate control in their newer models cars. All Tesla models now come equipped with a heat pump that handles both heating in the winter and cooling in the summer. There is also “cabin overheat protection” that can prevent your car from getting too hot, to begin with. It’s easier to stay cool when the car never gets sweltering! Teslas also have a “dog mode,” which allows you to keep the air conditioner running in your car while the car is stationary.
The other revelation in the Tesla range data is that at best, most Teslas get only 60% of their EPA range under normal operating conditions. Of course, some drivers actually get range numbers that align with the advertised mileage, but many fail to.
The air conditioner in a Tesla is variable speed, so depending on your cooling needs, it can use as little as ~1 kW or as much as 6 kW, although it generally is between 1 and 3 kW. With the AC keeping your cabin at a reasonable temperature in 90 degree weather, you can expect minimal range loss.
The chart below shows observed temperature variation for a selection of our Teslas.
For the Model 3, this data represents 2,540 vehicles and 194,000 data points.
For the Model Y, this data represents 765 vehicles and 60,500 data points.
For the Model S, this data represents 158 vehicles and 11,000 data points.
For the Model X, this data represents 123 vehicles and 8,200 data points.
