A power storage apparatus includes at least one battery module and a charging module. Each battery module includes a battery assembly, a protection unit, and a detection unit. The protection unit is connected in series to the battery assembly. The detection unit is connected in parallel to the protection unit, and the detection unit has an indication element. The charging module is connected in parallel to the at least one battery module to charge the battery assembly. When a voltage difference value of the protection unit is greater than a voltage setting value, the voltage difference value enables the indication element. Accordingly, simple circuit components installed in each battery module are used to individually protect the battery module and detect an abnormal operation of the battery module.