A single ageing battery cell could be holding back an entire electric vehicle. Even when most cells remain in good condition, one deteriorating component can limit the performance and useful life of the whole battery pack.

Researchers at Sweden's Chalmers University of Technology have investigated a solution that could change this.

Their study, published in Nature Communications, suggests that intelligent battery systems capable of bypassing weaker cells could extend battery lifespan by more than 20% under favourable conditions.

The technology could eventually help drivers keep their vehicles for longer while reducing replacement costs and demand for raw materials.

Why One Weak Cell Matters

Electric vehicle batteries contain hundreds or thousands of individual cells connected in carefully designed arrangements.

Although these cells work together, they do not deteriorate at identical rates. Temperature differences, manufacturing variations and repeated charging cycles can cause some to lose capacity faster than others. In conventional battery systems, weaker cells can restrict how much energy the entire pack can safely deliver.

This means a battery may become less useful even when many of its individual cells still have considerable capacity. Researchers believe that managing these differences more intelligently could improve battery durability without requiring entirely new chemical materials.

How The Technology Works

The proposed solution involves reconfigurable battery packs equipped with electronic switches and advanced control systems.

These components allow the battery to change how individual cells or groups of cells are connected.

When a cell becomes significantly weaker, the system can bypass it while continuing to use the remaining healthy cells.

This flexibility could prevent isolated deterioration from unnecessarily reducing the performance of an entire battery.

The researchers examined different configurations, including systems capable of controlling every cell independently.

Although individual control offers the greatest potential benefits, simpler arrangements involving groups of cells may be more practical for commercial vehicles.

How Much Longer Could Batteries Last?

Computer simulations suggest that advanced reconfigurable batteries could achieve lifespan improvements exceeding 20% in certain high-voltage vehicles.

Electric trucks and long-range passenger cars could benefit particularly because their battery packs contain many cells connected in series.

To illustrate the potential, researchers modelled an 80-kWh battery used for approximately 12,000 kilometres annually.

If a conventional battery reached a replacement threshold after ten years, the reconfigurable version could reach the same condition approximately 14 months later.

However, the results are based on simulations. Actual improvements would depend on battery design, operating conditions and the effectiveness of the control system.

Could Electric Cars Become Cheaper?

Battery replacement is one of the most significant potential expenses associated with older electric vehicles.

Extending battery life could therefore improve long-term ownership costs and help vehicles retain their resale value.

The researchers also identified possible advantages during manufacturing.

Battery producers currently spend considerable effort testing and matching cells with similar characteristics.

Reconfigurable systems could tolerate greater differences between cells, potentially simplifying production and reducing associated costs.

However, the additional electronic components would make these batteries more expensive to manufacture initially.

Environmental Benefits Beyond Driving

Longer battery lifespans could reduce demand for replacement packs and the materials needed to produce them. The technology may also improve opportunities for second-life applications.

When electric vehicle batteries become unsuitable for driving, some can still provide useful energy storage for buildings or renewable electricity systems.

A design that manages weaker cells individually could make it easier to continue using the remaining capacity.

When Could Drivers Benefit?

Reconfigurable batteries have already been explored in research and industrial prototypes, but they are not yet available in mass-produced vehicles.

Engineers must establish whether the improvements justify additional hardware costs and ensure that the systems remain reliable throughout years of operation.

Further development could make battery management an increasingly important part of electric vehicle innovation.

For drivers, the eventual result could be a battery that remains useful for longer, costs less over its lifetime and makes better use of valuable resources.