Insights / How does winter weather affect your EV batteries?

How does winter weather affect your EV batteries?

15th November 2021

What effect do colder temperatures have on EV range and performance – and what can you do about it?

Electric vehicles (EVs) are powered by lithium ion (Li-ion) batteries. They don’t perform at optimal levels in extreme weather, either hot or cold.

Diesel and petrol engines are also less efficient in cold weather. We tend not to notice it because they’re a technology we feel more familiar with. So, it’s not a new issue – and it isn’t exclusive to EVs.

How does extreme weather affect EV batteries?

Li-ion batteries are less efficient in extreme weather because their power comes from electrolyte fluid that functions best in moderate temperatures. In extreme cold, the electrons in that fluid move more slowly than in warmer temperatures.

Batteries in the latest EVs are less susceptible to cold than those of previous generations. This is partly thanks to sophisticated thermal management systems designed to keep the batteries within their optimal temperature range. These systems keep the electrons moving at the right rate, though they, too, depend on battery power.

It’s still true that in extremely cold weather, EV range will be affected. (Some vehicles even display special cold weather icons to indicate that the cold is restricting their range.)

This reduction in range shouldn’t be dramatic. Experts explain that ‘we would expect the loss in range to be 10-15 miles for a car with an overall range of around 160 miles’.

With a fully charged battery, this still leaves enough range for the vast majority of journeys made by fleet drivers. And improved logistics and planning, informed by real-life driving data, can help to design the problems out, to an extent.

Extreme cold weather also affects EV charging, with the amount of fast charging limited to protect batteries. This means your drivers may need to allow more time to power up their EVs.

So, while it’s true that winter weather can result in some range restrictions, it’s unlikely to keep your fleet off the road.

What can you do about it?

Here are a few tips to help mitigate the effects of cold weather on your EV fleet’s battery performance:

  • Keep the battery charged up – never let charge levels get too low. Try to keep at least 20% of charge in case the car needs to use power to warm the battery for recharging.
  • In really cold weather, use mains power from a charger rather than battery power to warm the interior of your EV before you set off.
  • Some EVs can capture waste heat from braking or other processes, using that to heat the car. If possible, make use of this feature rather than running the heating, as heating and cooling can cause a greater reduction in range than the weather conditions.
  • Drive in Eco mode if available, which generally uses less power.
  • Use regenerative braking where possible to help keep the battery topped up.

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Whether you’re a fleet, facilities, or energy manager, we can support your journey to a more electric future. To learn more about our end-to-end electrification offering - including My Electric Vehicles - get in touch.

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