Electric vehicle batteries have improved dramatically over the past decade, but degradation is still a concern for those planning to keep their cars for years. Even when most battery cells remain healthy, a handful of weaker ones can limit the performance and usable capacity of an entire pack.
Researchers in Sweden believe they have found a clever way around this problem. Instead of allowing aging cells to hold back the rest of the battery, their proposed system can effectively take them out of the equation.
A new study led by Chalmers University of Technology suggests that this approach could extend battery lifespan by over 20% under certain ideal conditions. The findings were published in the scientific journal Nature Communications.
The technology, known as a reconfigurable battery architecture, could also reduce long-term ownership costs and battery waste. However, it’s still experimental, with no mass-produced electric vehicles currently using the system.
Why One Weak Cell Can Limit An Entire Battery
An EV battery contains hundreds or thousands of individual cells connected into larger assemblies. Because these cells age at different rates, some gradually lose capacity faster than others.
In conventional battery configurations, weaker cells can restrict how much energy the entire pack can safely deliver or accept. This means otherwise healthy cells may not be used to their full potential.
The researchers propose introducing switches and intelligent controls that can change electrical connections within the battery. This would allow the system to bypass weaker cells while continuing to use the remaining healthy ones.
Battery Life Could Increase By Over 20%
According to the study, the most advanced configuration could extend battery lifespan by over 20% in certain high-voltage vehicles. However, this represents a theoretical upper limit involving individual control of every cell.
A more practical arrangement would control groups of cells together, potentially offering smaller but still worthwhile improvements. In one example, researchers also modeled an 80-kWh battery in a vehicle driven 12,000 kilometers annually.
Assuming a conventional pack reaches its replacement threshold after 10 years, the reconfigurable design could last approximately 14 months longer. An improvement like that would be extremely valuable for commercial fleets with hundreds of vehicles
Longer Life Could Mean Lower Costs
The additional electronics would increase manufacturing costs initially, but researchers believe longer service life could offset that expense. Improved residual battery value could also benefit owners and commercial fleet operators.
There are potential environmental advantages, too. Batteries could stay useful for longer, while retired packs might retain enough healthy cells for stationary energy storage applications.
Promising Technology, But Not Production-Ready
The concept has already been explored in research and industrial prototypes, although we’re still not at the point of widespread commercial adoption. Manufacturers would need to balance additional complexity, reliability, and production costs against the expected benefits.
The research suggests that improving EV battery longevity may not require entirely new battery chemistry. A smarter approach to managing individual cells could help manufacturers extract greater value and longer service life from existing battery technology.
The additional lifespan would depend on factors such as battery chemistry, pack configuration, vehicle type, and operating conditions. While the researchers identified the potential for improvements exceeding 20%, the actual benefits could vary significantly once the technology reaches production vehicles.