Smarter batteries last longer

A battery system with built-in intelligence could improve the range of electric vehicles and also help push the price of batteries down. Developed by the Fraunhofer Centre for Manufacturing Engineering and Automation in Stuttgart, the system allows the individual cells that make up a battery module to communicate with each other, allowing the entire module to use the available charge in the cells in a more efficient way than is currently possible.

Large batteries like those in electric vehicles are composed of a number of cells linked in series. In theory these all have the same capacity, but in practice they vary slightly because of manufacturing variability. The unfortunate consequence of this is that the whole battery is effectively only a strong as its weakest cell; when this is depleted, regardless of the charge state of the other cells in the array, the whole battery has to be recharged. And if a cell stops working altogether, the whole battery becomes useless.