Electric vehicles demand up to 70% more power in winter, reveals ADAC and Green NCAP study
Cold temperatures, not only affect the passengers in an electric car but also the traction battery. The need for warm air, heated seats, steering wheel, and windows increases electric power consumption, a factor unseen in combustion vehicles where heat is a byproduct of the engine's operation.
Although an electric car driver could choose to forego heating to lower power consumption, they cannot control the battery heating. The battery's chemistry performs best at temperatures between 68 and 104 degrees Fahrenheit, which ensures optimal cell performance.
However, heating a substantial battery, which may weigh several hundred kilograms, in winter requires considerable energy. The larger the cell capacity and the colder the temperature, the more power needed to achieve the optimal working temperature. These findings are based on ADAC's investigations and tests conducted by Green NCAP.
The tests by Green NCAP use the WLTP measurement cycle and are carried out in a lab, specifically on a "roller". Completed over 30 minutes, the tests simulate a car "traveling" a distance of around 14 miles. The tests were run in thermal chambers at 73.4 degrees Fahrenheit and 19.4 degrees Fahrenheit, mimicking scenarios where the car spent several hours outside overnight, without being charged at home, before being driven on city, suburban, and expressway routes.
Winter conditions resulted in an average 70% increase in the power consumption of the tested cars compared to summer. Particularly, the Renault Kangoo and Volkswagen ID.5 demanded twice as much electricity at 19.4 degrees Fahrenheit than at 73.4 degrees Fahrenheit. The smallest increase in consumption was noted in BYD Atto 3 (+38%) and Dacia Spring (+39%), which has the smallest battery in the test group, having a gross capacity of 26.8 kWh.
Green NCAP experts used these measurements to calculate theoretical ranges at 73.4 degrees Fahrenheit and -19.4 degrees Fahrenheit. Such winter measurements, while pessimistic in nature, are true for those who often travel short distances with long stops causing the car to cool down. Following this, they have to reactivate the heating.
The calculations by Green NCAP show that in some cases, only half of the summer range is left during cold temperatures. It also points out different heating strategies of different models. The BYD Atto 3, for instance, loses only 64 miles of range in winter but heats the cabin very slowly. Renault models, on the other hand, have varying interior heating. The interior of the Megane can heat up to 88.2 degrees Fahrenheit, while the Kangoo's high cab reaches a temperature that is 25.2 degrees Fahrenheit cooler at the same time.
ADAC uses a slightly different testing method, with consumption measured at 32 and 68 degrees Fahrenheit on the testing grounds of the ADAC center in the town of Penzing. The route covers 62 miles, and the car travels at speeds of 18, 31, 50, and 75 mph. This method provides controlled conditions, unaffected by traffic variability.
The ADAC tests revealed significant differences between summer and winter power consumption, although smaller than the Green NCAP findings due to a milder winter measurement temperature and a longer driving section. Thus, energy needed for heating gets evenly distributed over that distance.
ADAC also recorded the summer and winter consumption of their long-distance test vehicles. These values were logged from the onboard computers. Different drivers drove the cars on various routes with varying traffic intensities. Regardless, the trends were similar, with equivalent percentage increases in consumption for Volkswagen and Renault. The Opel model required a quarter more electricity in winter than in summer.
During winter, drivers should factor in a reduced range and plan their routes accordingly. Navigation from the manufacturer, which adjusts charging stops automatically, can be useful. However, when you have to manually alter routes or add additional charging stops, the process becomes more cumbersome.
ADAC experts also highlight the increase in fuel consumption in combustion cars during winter. According to Green NCAP data, gasoline engines consume an average of 15% more fuel in winter than in summer, while diesel engines use up to 24% more.