Method of inspecting power storage device and method of producing the same

A method of inspecting a power storage device, the method comprising:

• connecting a positive terminal of the power storage device with a positive terminal of an external power supply via a positive-side conductor, and connecting a negative terminal of the power storage device with a negative terminal of the external power supply via a negative-side conductor, to form a circuit, and placing a resistance path between the positive-side conductor and the negative-side conductor, the resistance path including a resistor and a switch connected in series;
• setting a length of an ON time for which the switch is temporarily closed before start of inspection of the power storage device, according to a storage capacity of the power storage device, such that the ON time is longer as the storage capacity is larger, and the ON time is shorter as the storage capacity is smaller;
• after the resistance path is placed, temporarily closing the switch over the ON time to be set, obtaining an ON voltage as a voltage between the positive-side conductor and the negative-side conductor within the ON time, and an OFF voltage as a voltage between the positive-side conductor and the negative-side conductor at a time other than the ON time, and calculating a parasitic resistance value of the circuit, based on a voltage value of the ON voltage, a voltage value of the OFF voltage, and a resistance value of the resistor;
• and
• after the parasitic resistance value of the circuit is calculated, applying a voltage of the external power supply to the power storage device in a condition where the switch is open, and inspecting the power storage device using a current value of the circuit, while increasing the voltage of the external power supply, according to the parasitic resistance value, within a range in which an absolute value of an imaginary resistance value is kept smaller than the parasitic resistance value of the circuit, the imaginary resistance being a negative value obtained by converting an amount of increase of the current value of the circuit when the voltage of the external power supply is increased, into an amount of reduction of the parasitic resistance value of the circuit, the power storage device being inspected using the current value of the circuit, by determining whether a self-discharge current of the power storage device is larger or smaller than a predetermined value, based on a condition of convergence of a circuit current flowing in the circuit.