With temperatures bottoming out across the country, electric vehicle drivers are probably noticing their driving range plummeting. Here’s why it keeps happening – and there’s more to it than you might think. -(CNN)
Studies conducted by the consumer advocacy organization Consumer Reports revealed that electric vehicle (EV) range experiences an average decrease of approximately 25% during highway cruising in sub-freezing weather compared to milder temperatures. The reduction in driving range, referring to the distance an EV can cover before requiring a recharge, can be attributed to two primary factors: the battery itself and the driver. Andy Garberson, Head of Marketing at Recurrent, an EV battery research company, highlighted that both human beings and EV batteries perform optimally within a similar temperature range, typically ranging from the mid-60s to mid-70s Fahrenheit.
Batteries function through intricate chemical reactions involving the movement of electrons and ions from one side of the battery to the other. In colder temperatures, various chemical reactions, including those within a battery, experience a slowdown, leading to a decrease in driving range.
Similarly, human beings also face challenges in cold weather. When driving on chilly days, we often find it necessary to increase the heat. Interestingly, this aspect plays a more significant role in diminishing the range of electric vehicles than the direct impact of temperature on the battery, as emphasized by Garberson.
In contrast, the impact of turning on the heater in a gasoline-powered car on fuel economy is minimal. Gas engines consistently generate a significant amount of heat, irrespective of the season, be it summer or winter. Interestingly, when a gasoline-powered car burns fuel for propulsion, a substantial portion of the energy is transformed into waste heat rather than kinetic motion. Consequently, redirecting some of this surplus heat into the cabin for passenger warmth poses negligible challenges.
Electric motors and batteries, in contrast, generate minimal waste heat, contributing to their high efficiency. Nearly all the energy stored in the batteries is utilized for driving, enhancing overall efficiency. However, when heating is required for the cabin, the energy dedicated to this purpose is deducted from the potential driving miles, resulting in a significant reduction in driving range.
Consumer Reports’ evaluations of electric vehicles highlighted that frequent short trips exacerbated the situation. Each time the vehicle came to a stop and the cabin cooled down, reheating was necessary upon restart, consuming additional energy and doubling the amount of lost range.
Fortunately, most newer EV models have very efficient heat pump heating systems that help minimize the impact. But even those systems have their limits, and don’t work well when temperatures drop below about 14 degrees Fahrenheit, said Garberson.
Charging electric vehicles takes longer in colder temperatures due to the impact on the chemical reactions involved in both charging and discharging. These reactions, crucial for powering the car, experience a slowdown in colder weather, prompting some electric vehicles to significantly reduce their maximum fast charging capabilities in extreme cold to avoid potential battery damage.
Fortunately, modern electric vehicles come equipped with advanced temperature management systems. According to Garberson, these systems actively maintain the battery pack’s temperature close to the optimal range. Additionally, if a driver sets an electric vehicle fast charger as the destination in the navigation system, the vehicle proactively prepares itself for the charging process.
