- New EV battery design can extend lifespan by over 20%.
- The architecture allows current to bypass aging cells, improving battery performance.
- Research shows extended lifespan can offset additional costs, based on computer simulations.
- The technology has not yet been realized in mass production; further testing is needed.
Swedish researchers say a new electric vehicle battery design can extend battery life by allowing current to bypass aging cells, with an expected improvement of over 20%. The architecture uses electronic switches and a control system to change how cells are connected during operation. Researchers at Chalmers University of Technology found that this method can significantly improve battery life in high-voltage vehicles, including electric trucks and long-distance passenger cars. In a simulated example involving an 80-kilowatt-hour battery, the system delayed battery replacement by about 14 months.
The researchers also found that the extended lifespan and higher residual value can offset the additional cost of the electronics. These findings are based on computer simulations, not long-term testing in production vehicles. The researchers said the maximum lifespan improvement represents a theoretical upper bound under ideal conditions.
How the new architecture works
Conventional EV batteries contain many interconnected cells whose capacity gradually decreases over time. Because cells degrade at different rates, a single damaged cell can limit the usable capacity of the entire pack. The proposed architecture addresses this limitation by allowing switches to disconnect weaker cells while keeping healthy ones operational. Instead of relying on fixed electrical connections, the battery management system can adjust how cells are connected based on their condition. "In our study, this solution enables the battery to bypass problematic cells and continue operating."
Albert Skogro, the study's first author and a doctoral student at Chalmers, said.
The researchers used experimentally validated battery models and large-scale simulations to examine different cell chemistries, pack configurations, operating conditions, and aging patterns. Each scenario included 1,000 Monte Carlo simulations to account for variation between cells. Their analysis also considered 20 representative EV models from 15 manufacturers. Potential lifespan improvements generally increase with battery voltage, making the approach particularly promising for vehicles with many cells in series. However, the maximum benefit requires individual control of each cell.
Commercial designs are more likely to control cells in groups to reduce hardware complexity and cost.
Economic viability analysis
The researchers also examined whether the additional electronics make economic sense. In one scenario, they simulated an 80-kilowatt-hour battery driven 7,456 miles per year. A conventional battery reached its assumed replacement point after 10 years, while the reconfigurable design extended that timeline by about 14 months. The analysis identified favorable economic conditions for packs with capacities above roughly 50 kilowatt-hours, annual mileage below 7,550 miles, and additional upfront costs under 7.16%. The technology can also reduce the need for precise matching of cells during manufacturing, since the pack can better accommodate variations in cell performance.
The researchers said the method could allow more retired EV batteries to be repurposed for stationary energy storage.
The technology has undergone research and industrial prototype testing but has not yet been deployed in mass-production vehicles. Long-term vehicle testing is still needed to determine whether the simulated lifespan and cost benefits can be realized in practice. The research was conducted with industry partners including Scania and PHINIA and published in Nature Communications.
Impact of this technology on the EV market
The potential of the new EV battery design lies not only in extending battery life but also in improving overall performance, which is crucial for the development of the EV market. As EV demand grows, increasing battery lifespan and performance can reduce replacement frequency and lower user costs. The study shows this design can effectively address conventional battery degradation issues and may promote the reuse of retired batteries, having a positive impact on environmental protection and resource recycling. However, the technology still requires further testing to ensure its feasibility and economic viability in real-world applications.