Chalmers Study: Reconfigurable Battery Packs Could Add Years to EV Life

A new study out of Chalmers University of Technology suggests that electric vehicle batteries could live considerably longer if packs were designed to route around their weakest cells rather than being limited by them. Conducted with involvement from Phinia and Scania, the research puts the potential gain at more than 20% in certain high-voltage applications — a figure that assumes every individual cell can be switched on its own, making it a theoretical upper bound rather than a guaranteed real-world result.

The underlying problem is uneven aging. Cells inside a pack never degrade at the same pace, and in today’s conventional architectures the most degraded cell effectively caps the performance and lifespan of the entire battery. Reconfigurable packs flip that logic: switches paired with control software allow the system to bypass a failing cell and continue drawing power from the healthy ones. According to the study, the greatest benefits would accrue to electric trucks and long-range passenger cars, where battery strain and replacement costs are highest.

The researchers modelled an 80 kWh car battery driven 12,000 km per year. In that scenario, a reconfigurable pack reached its replacement threshold at roughly 11 years — about 14 months later than a conventional pack, which was retired at the 10-year mark. That extra service life does not come free: the added switching electronics push up upfront costs. The study argues, however, that the longer lifespan and improved residual value would offset the premium across many realistic use cases.

The implications extend beyond the road. If packs can tolerate wider variation between individual cells, manufacturers could reduce the extensive testing and matching work currently required during production. More packs might also qualify for a second life as stationary energy storage once they are retired from vehicles. Still, the technology remains at an early stage — so far it exists only in research settings and industrial prototypes, not in series production.

Changfu Zou, a professor in Chalmers’ Department of Electrical Engineering and a co-author of the study, framed the trade-off as a design choice rather than a binary: reconfiguration is not a question of ‘on or off’, he said, describing it as a spectrum, with the position a manufacturer chooses determining how much of the potential benefit can actually be realised. In effect, the work points to a shift in how the industry thinks about battery durability — less a matter of cell chemistry alone and increasingly one of control electronics.