A secondary battery protection circuit may include an over voltage detector circuit configured to monitor a voltage level of an associated cell of a rechargeable battery and provide an output signal to a switch in response to a comparison of the voltage level of the cell to an over voltage threshold level. The switch may be coupled between the rechargeable battery and a DC power source and capable of moving between conducting and non-conducting states. The switch may also be responsive to the output signal to protect the rechargeable battery if the voltage level of said cell is greater than the over voltage threshold level for a time interval less than or equal to a transient time interval.