A charge/discharge control circuit for controlling the charging and discharging of a secondary cell has a voltage dividing circuit for dividing an output voltage of the secondary cell, which may comprise plural cells, an overcharge detection circuit for detecting an overcharge state of the secondary cell, an overdischarge detection circuit for detecting an overdischarge state of the secondary cell, and a control circuit for receiving and processing an output signal of the overcharge detecting circuit and the overdischarge detecting circuit and controlling the switch. In a preferred embodiment, an overcharge reference voltage source used for the overcharge voltage detection circuit is used also as an overdischarge reference voltage source for the overdischarge voltage detection circuit.