Management of serially-connected battery system using multiple switches

When charging and discharging battery cells in series connection, it is recommended that a deteriorated cell displaying unbalanced voltage should be removed without interrupting the charging and discharging processes. The authors have proposed a novel circuit whereby battery cells are serially connected, which controls multiple switches by measuring the cell voltages. This circuit makes balanced charging and discharging possible even for the cells containing a deteriorated cell. Their experiments on the proposed circuit´s performance using lithium-ion cells obtained satisfactory results.