How Does Temperature Affect an EV's Range?
In one word, adversely.
Compared with internal-combustion cars, electric vehicles are pickier about the conditions in which they operate. Neither the battery nor the people inside the car want to sweat or freeze, but keeping them comfortable on hot or cold days takes energy, which comes from, you guessed it, the battery itself. Alas, any energy used to keep the pack and occupants at their ideal temps won’t go toward moving the EV down the road, and range suffers. Fortunately, there are things you can do to minimize the impact of extreme temperatures on your EV’s range and your range anxiety.
Why Do Extreme Temperatures Reduce EV Range?
Much like Goldilocks, EV batteries don’t like things to be too hot or too cold. To keep packs working at their most efficient levels, automakers equip EVs with systems to cool and heat their battery packs as needed. Such systems draw power from the pack at the expense of range. How big is the effect? According to a
What’s more, some EVs won’t allow fast-charging when the pack is too cold, as that could damage the battery. The battery management system must heat the battery to an acceptable temperature first. And if you’re in a hurry, you’ll need to spend precious minutes bringing the battery to temp first before recharging, which in effect limits your range.
While cold temperatures influence range more than hot ones, running or even parking an EV in excessive heat can cause permanent battery degradation, which means that over time, your car won’t go as far on a charge as it once did.
How Do Cabin Heat and A/C Use Affect EV Range?
Along with the battery, you and your passengers will want to be comfy, too. Maintaining a pleasant cabin climate also requires energy. How much? Again, we turn to the aforementioned AAA study, which found that setting the HVAC to 72 degrees in 20 degree weather decreased average range by an additional 29% (for 41% total, when factoring in the effects on the battery) compared with average range at 75 degrees with the HVAC off. In 95 degree heat, the figure dropped another 13% (for 17% total).
How Can I Maximize Range in Extreme Temperatures?
There are things you and your EV can do to combat temperature-related range depletion. This starts before you set off. An EV can pre-heat and pre-cool its pack and interior when plugged into a charging station. Most provide a way to schedule climate adjustment or request it remotely, so if you know you have to leave for work at a set time, you can program the car to precondition both the cabin and the battery temperature using power from the wall prior to your departure. Assuming the vehicle is fully charged prior to preconditioning, it preserves its full range, and you won’t waste potential mileage making yourself and the battery comfortable.
When it’s cold out and you want to warm up efficiently, use heated seats first, turning to the HVAC system only when needed. That’s because conductive heat transfer from the seat to your backside requires less energy to warm you than making and blowing hot air in your direction. You can also bundle up, especially on short trips, to avoid using the HVAC. And remember that, without an engine to draw heat from, EVs rely on resistive heaters and heat pumps to supply warmth, and these things take a little while to warm up, so keeping your hat and gloves on until they kick in is just common sense.
Lastly, pay attention to where you park. A temperate garage is ideal, but staying out of direct sunlight in the summer will cut down on how much the A/C has to run, while seeking a sunny spot in winter will reduce your cabin climate usage. The key is to protect your electric cars in cold weather and hot weather.