EV batteries last longer than expected, study finds

20 December 2024

Electric car adoption is rising, but concerns about battery life and range anxiety still worry many potential buyers. A new study published in Nature Energy offers promising insights, suggesting that EV batteries might actually last significantly longer than previously estimated by manufacturers' accelerated lab tests.

Traditional testing involves quick cycles of charging and discharging to estimate the lifespan of a battery. Unfortunately, this approach doesn't accurately reflect how we use EV batteries in real-world scenarios. The Nature Energy study took a different approach. The researchers examined 92 commercial lithium-ion batteries over two years, using four distinct discharge profiles to simulate various driving scenarios.

Surprisingly, the study found that EV battery life expectancy is significantly influenced by "time-induced aging," or the natural degradation of the battery over time, rather than just the number of charge-discharge cycles. This means that factors like frequent acceleration and braking, short trips with rest periods, and even letting the car sit idle for a while can actually contribute to a longer battery life.

"To our surprise, real driving with frequent acceleration, braking that charges the batteries a bit, stopping to pop into a store, and letting the batteries rest for hours at a time, helps batteries last longer than we had thought based on industry-standard lab tests," said Simona Onori, the study's senior author and an associate professor at Stanford Doerr School of Sustainability.

The findings challenge the assumption that constant charge-discharge cycles were the main culprits behind short battery life. While this is true for commercial vehicles in continuous operation, it doesn't really apply to consumer EVs, which experience more varied usage patterns.

The study's results have significant implications for the electric car industry. Automakers should be able to optimize battery management software, and extend battery life. Given that batteries constitute a substantial portion of an EV's overall cost, keeping them going for longer is particularly important.

Speaking of costs, the good news continues. EV battery prices have been steadily declining, dropping by 20% in 2024 alone. Fast-growing production and cheaper materials have driven the average battery pack price down to $115 per kWh. Experts predict the prices will fall below $100 per kWh by 2026 and even reach $69 per kWh by 2030.

These falling prices are great for consumers, but they also present challenges for the industry. A potential oversupply and price wars among major battery producers like CATL and BYD can put pressure on smaller automakers. Some of them might be forced to reduce profit margins or face bankruptcy.

The Nature Energy study provides important assurance about battery longevity, addressing a key concern for potential EV buyers. Add to it the falling battery prices, and we can expect to see EV costs closer to parity with internal combustion engine vehicles in the coming years.

Source 1 | Source 2