The Truth About Electric Vehicle Range Testing in Real Conditions

Last month a government-funded initiative led by the Australian Automobile Association (AAA) to establish real-world electric vehicle (EV) driving ranges showed that some electric cars don’t travel anywhere near as far as they claim to.

While these findings aren’t particularly startling given manufacturers’ published figures for both internal combustion and electric vehicles are derived from laboratory tests in controlled settings that frequently don’t mirror real-world conditions, in this instance the range figures may have been further exaggerated because of a detail most overlooked – the temperatures at which those tests were carried out.

EVs experience substantial range loss in very cold and very hot conditions. The ideal operating temperature for a battery-powered vehicle is between 20-25 degrees Celsius. Although the fuel use of combustion vehicles will also shift in colder or hotter weather, the variation is nowhere near as pronounced as with EVs.

When the ambient temperature or the battery temperature inside an EV falls outside that optimal window, the car must draw on its own battery power to either warm or cool the battery, which effectively reduces the usable battery capacity for driving and providing propulsion.

According to the report posted on the AAA website, testing took place on two occasions on roads around Geelong in Victoria at temperatures of 25 degrees Celsius and 17 degrees Celsius. Both temperatures are within cooee of absolutely optimal test temperatures for an EV. Despite this, the BYD Atto 3 still recorded an average range decrease of 23 per cent compared with its advertised range.

To give some perspective on how much worse it can become, the American Automobile Association (another AAA) observed range drops in EVs of up to 40 per cent during trials in freezing conditions (-6 degrees Celsius) when the heater was in use, with ranges improving as temperatures moved closer to the ideal band.

So, if we are observing range losses during testing at near-optimal temperatures, as we did with the BYD Atto 3 and others, you can also expect range to fall even further when driving in cold weather.

Melbourne, for example, has average winter morning temperatures of between 2-13 degrees Celsius. If you commute while it’s cold or drive at night in winter you’re likely to face notable range reductions.

If you own an EV and grasp how and why this occurs and then allow for it, it’s not a problem at all. I will, for instance, factor in 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 salesman at the dealership will never tell you this when pitching 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 vehicle online.

‘Real-world’ EV range results like this, particularly when they’re based on testing financed by taxpayers, should be released with more detail clarifying that they represent almost best-case scenarios in ideal circumstances.

Buyers should be able to make informed choices when public money is used to promote these findings, instead of being given information that hides the reality of driving an EV during colder months.