In today’s electric vehicle batteries, the weakest cells can limit the lifetime of the entire battery pack, even when most of the cells are still performing well. Researchers at Chalmers University of Technology, together with industry partners, have investigated a battery architecture that can instead bypass cells that have deteriorated. In the models, the technology could extend battery lifetime by more than 20 percent under certain conditions. In a representative use case, it defers battery replacement by around 14 months while also reducing overall costs.
A battery pack in an electric vehicle consists of many interconnected battery cells. However, the cells are not identical. Differences arise during manufacturing and can become more pronounced as the battery is used and ages. Some cells therefore lose capacity faster than others. (....)