Hot and cold behaviour: how EV batteries are affected by extreme temperatures
EVs are an integral part of a cleaner, more sustainable future. And to enable widespread electric vehicle adoption, they must be optimised for all environments and conditions. After all, whether 25° C or -25° C, the tailpipe emissions still need to be zero.
Range anxiety is a common factor for potential EV owners, and as the temperature drops during winter that anxiety may grow. It’s true that range gets affected as it gets colder but it’s important to note that reduction of range is temporary. Additionally, some adjustments can minimise the impact of the cold.
Since the cold affects the electrochemical reactions happening inside the EV battery and slows everything down, charging time may increase during winter. Making sure the battery is above freezing before charging can help to avoid lithium plating, which will cause aging and degradation of battery performance. However, most electric vehicles have some type of temperature regulation in their battery system that will prevent high voltage if the battery is too cold.
An AAA study concluded that temperature alone could reduce range by 10-12% and that the use of in-vehicle climate control could amplify loss of range to up to 41%. Storing and charging an EV in a heated garage will help the battery to tackle cold winters more efficiently, and it will significantly reduce charging time as well.
It's a good idea to pre-heat an EV while charging because instead of drawing energy from the battery, it uses the power from the outlet to heat up. Doing this will maximise range, as it takes less energy to remain at a certain temperature than to change it.
Now, let’s move from one side of the thermometer to the other.
Temperature has a big impact on battery degradation since it affects the chemical reactions inside the battery. Just like cold temperatures slow everything down, higher temperatures can create faster reactions, which can lead to unwanted ones that make your battery degrade faster.
Storing an EV in a cool location, such as a garage, will ensure that the battery is kept at optimal temperatures. Although (as stated earlier) most EVs have a battery management system that monitors the temperature, which will prevent charging if the battery is too warm. There are some concerns amongst EV owners that it might be unsafe to drive during extreme heat because of the battery. Thankfully, this is not the case. EVs are safe to operate during any type of weather, even during extreme heat. Just plug in, charge up, and hit the road.
A study shows that range may decrease by 17% when air conditioning is used while driving. As stated above, climatizing and pre-conditioning are key to tackling extreme cold, and the same goes for the heat.
During longer trips, driving under cooler conditions, when possible, can maximise range. Limiting the weight in the car by not packing it to capacity, as well as avoiding excessive accelerating and braking, are other ways to get as much range as possible.
While it is true that extreme temperatures will have some negative impact on an EV’s battery and therefore its range, there are plenty of things that will minimise these impacts and maximise the capacity of the EV battery. No vehicle is immune to extreme weather conditions (not even gas-powered ones). And with some extra planning and adjustments, an EV can be on its best behaviour, regardless of temperature.
Staying current about current: the latest from the world of batteries
Everyone knows that EVs have batteries. Keeping up with the ever-evolving world of batteries, however, is a different story. Which is why we decided to break it down. In this series, we will explore the state-of-the-art of EV batteries, answer the most common questions about their second life applications, and provide a breakdown of cutting-edge battery technology.