Ngalula Mubenga, an electrical engineer at the University of Toledo, has developed a new technology referred to as a “bilevel equalizer.” The device combines the high performance of an active equalizer with the low cost of the passive variety. The technology arranges cells into sections where each is balanced by a passive equalizer. The entire section is balanced by an active equalizer. Mubenga said the solution could help electric vehicle batteries hold their charge longer.
A lithium-ion battery is only as strong as its weakest cell. Since batteries are constructed in a series of cells, one bad cell can disable an entire energy storage system. Balancing the battery load often requires an equalizer consisting of either a passive circuit, which can be inefficient, or an active circuit, which is far more expensive. Read more