A battery protection circuit for protecting a secondary battery composed of a first cell and a second cell, includes a reference voltage supply circuit that outputs a first reference voltage and a second reference voltage generated based on cell voltages of the first cell and the second cell, respectively; a first detection circuit that outputs a signal prohibiting charging when at least one of the cell voltages of the first cell and the second cell exceeds a predetermined overcharge indication value; a second detection circuit that outputs a signal prohibiting charging when at least one of the first reference voltage and the second reference voltage is not within a predetermined target range; and a control circuit that controls to prohibit charging when at least one of the outputs from the first detection circuit and the second detection circuit is the signal prohibiting charging.