A charging system includes a vehicle, a charging/discharging connector, a detector, and an informing portion. The vehicle is equipped with an electric power storage device, and also includes an inlet for charging the electric power storage device. The charging/discharging connector is a connector that is attached to and detached from the inlet and that is connected to the inlet in a fully fitted state, in which charging can be performed, and a half-fitted state, in which charging is not allowed. The detector includes an electronic control unit for detecting whether a connecting state of the charging/discharging connector is the fully fitted state or the half-fitted state. The informing portion includes an indicator for informing a user of abnormal connection of the charging/discharging connector on the basis of a detection result of the electronic control unit when connection of the charging/discharging connector is the half-fitted state.