The present invention relates to a system for preventing battery overvoltage, and more particularly, to a system for preventing battery overvoltage using an existing balancing circuit.

Typically, a secondary cell applied/mounted to a device such as a mobile electronic device or an electric vehicle, which requires a rechargeable electrical storage device, is configured from multiple cells connected in series or in parallel.

In a process for charging the secondary cell including such multiple cells, when even any one cell among the multiple cells is charged with a voltage equal to or greater than a certain voltage, a dangerous problem such explosion or ignition may arise. Such cell overcharge is typically a cause of cell overvoltage and affects other cells except the overvoltage cell, and thus results in a problem such as performance degradation or occurrence of failure. Accordingly, cell overvoltage is a cause of high risk inducing various problems, and thus prevention of such problems is important for a safety, performance, and the like of a secondary cell.