Aggressive driving degrades EV battery capacity 2.5 times faster, study suggests

Hard launches, repeated bursts of acceleration, and demanding high-current driving could significantly shorten the lifespan of an electric vehicle’s battery, according to a new study based on real-world driving data. Researchers at Shanghai Dianji University in China analyzed a year’s worth of driving data from 15 electric vehicles operating in Guangzhou in 2022. Their findings suggest that driving behavior itself could be a major factor in how quickly an EV battery ages. The study, published in Scientific Reports, found that the most aggressive driving style generated far higher battery-aging stress than smoother, more economical driving. Same road, very different battery stress The researchers collected data from the vehicles every 10 seconds, tracking factors including vehicle speed, battery current, state of charge, voltage, and temperature. They then used machine-learning methods to classify driving into five different styles, ranging from smooth “eco-driving” to highly aggressive operation. The most aggressive category was not simply defined by high speed. Instead, it involved repeated demands for high electrical current from the battery, including frequent high-torque acceleration at relatively low speeds. That distinction is important. An EV cruising quickly on a highway may not necessarily place the same kind of strain on its battery as a vehicle repeatedly launching from traffic lights, accelerating hard, braking, and accelerating again. The researchers used their machine-learning framework to separate the influence of driving behavior from other factors known to affect battery aging, including temperature, state of charge, and periods of idling. At the extremes, the difference between driving styles was substantial. The researchers found that the most aggressive category produced an aging stress rate 18.4 times higher than the eco-driving category. One reason appears to be the amount of electrical current demanded from the battery. The aggressive-driving group recorded an average root-mean-square current of 66.02 amps, compared with 20.56 amps for the eco-driving group. When the researchers modeled a scenario in which driving behavior alone was changed from aggressive to eco-driving while other conditions remained consistent, they found that short-term battery aging stress could be reduced by 91.3%. The results suggest that how an EV is driven may matter independently of factors such as climate and charging habits. The long-term difference could be dramatic The researchers also fed the characteristics of each driving style into a battery-aging model to estimate longer-term capacity loss. After 1,000 charge-discharge cycles, the model predicted that batteries associated with the smoothest driving style would lose around 21.15% of their original capacity. For the most aggressive driving style, however, the predicted capacity loss reached 53.22%. That is roughly 2.5 times as much capacity degradation. A battery with less usable capacity translates directly into reduced driving range, while degradation can also affect vehicle performance and resale value. Given that the battery pack is one of the most expensive components of an electric vehicle, even relatively small differences in its long-term health could have financial consequences for owners. A prediction, not a 1,000-cycle experiment There is an important limitation to the findings. The researchers did not directly observe the same vehicles for 1,000 charge cycles and measure their eventual battery capacity loss. Instead, they used real-world driving data to estimate battery stress and then applied a battery-aging model to predict the long-term effects. That means the 53.22% versus 21.15% figures should be interpreted as modeled projections rather than directly measured outcomes. Real-world battery degradation is influenced by a wide range of variables, including charging patterns, climate, battery chemistry, vehicle weight, terrain, traffic conditions, and thermal-management systems. Still, the researchers’ analysis consistently pointed in the same direction. Repeatedly demanding high currents from an EV battery appears likely to accelerate its aging. The takeaway is not necessarily that EV owners should drive slowly. Instead, smoother acceleration, less frequent hard launches, and avoiding unnecessary cycles of heavy acceleration and braking could help reduce stress on one of the vehicle’s most expensive components. In other words, the secret to making an EV battery last longer may not only lie in how it is charged, but also in what happens every time the driver puts their foot down.Get the latest in engineering, tech, space & science - delivered daily to your inbox.Kaif Shaikh is a journalist and writer passionate about turning complex information into clear, impactful stories. His writing covers technology, sustainability, geopolitics, and occasionally fiction. A graduate in Journalism and Mass Communication, his work has appeared in the Times of India and beyond. After a near-fatal experience, Kaif began seeing both stories and silences differently. Outside work, he juggles far too many projects and passions, but always makes time to read, reflect, and hold onto the thread of wonder.