The Truth About Electric Vehicle Range in Cold Weather Conditions

Last month a government-backed initiative run by the Australian Automobile Association (AAA) to assess real-world electric vehicle (EV) driving distances showed that some electric cars fall well short of their advertised ranges. While these findings aren’t particularly shocking given that manufacturers’ stated figures for both petrol-powered and electric cars are derived from laboratory tests under controlled conditions that often don’t mirror everyday driving, in this instance the range figures may have actually been inflated because of one detail most people overlook – the temperatures at which those tests were performed.

EVs endure marked range losses in extremely cold and very hot conditions. The ideal operating temperature for a battery-electric vehicle is roughly 20–25 degrees Celsius. Although fuel consumption for internal combustion cars will also change in colder or hotter weather, the variation is nowhere near as pronounced as for EVs.

When the outside air or the battery temperature in an EV falls outside that ideal band, the car must use its own battery energy to either heat or cool the battery, which effectively reduces the battery capacity available for propulsion.

According to the report posted on the AAA website, testing occurred on two occasions on roads around Geelong in Victoria at temperatures of 25 degrees Celsius and 17 degrees Celsius. Both temperatures are very close to the absolutely optimal testing temperatures for an EV. Even so, the BYD Atto 3 recorded an average range drop of 23 per cent versus its claimed range.

To show how much worse it can become, the American Automobile Association (another AAA) discovered EV range decreases up to 40 per cent during tests in freezing weather (-6 degrees Celsius) when the heater was used, with ranges improving as temperatures approached the optimal window.

So, if we’re seeing range declines during tests at near-optimal temperatures, like with the BYD Atto 3 and others, you can expect range to fall even more when driving in cold weather. Melbourne, for instance, has average winter morning temperatures between 2–13 degrees Celsius. If you commute when it’s cold or travel at night in winter you’re likely to face substantial range reduction.

If you own an EV and grasp how and why this happens and then allow for it, it isn’t a problem at all. I will, for example, assume a 40 per cent range reduction whenever I drive an EV in winter. For me it provides peace of mind that I’ll reach my destination.

But a salesperson at the dealership will never mention this when pitching you the idea of an EV. You also won’t find these specifics published anywhere on the Tesla or BYD websites, for example, if you’re ordering a car online.

‘Real-world’ EV range outcomes like this, particularly when they stem from taxpayer-funded testing, should be released with more context explaining that they reflect almost best-case scenarios under ideal conditions. Buyers ought to be able to make informed choices when public funds are used to promote these results, instead of being given information that obscures the reality of driving an EV during colder months.