A charger that charges a battery for a vehicle includes a cable unit, a plug-locking mechanism, a connector-locking mechanism, a current-voltage controller, a detector, a report controller, and an authenticator. The cable unit includes a charging plug that is plugged into the vehicle, a connector that is coupled to a charger's main body, and a charging cable coupled to the charging plug and the connector. The plug-locking mechanism locks the charging plug. The connector-locking mechanism locks the connector. The current-voltage controller applies test current and voltage to the charging plug. The detector detects abnormality of the charging plug based on a condition of the charging plug when the test current and voltage are applied to the charging plug. The report controller reports whether the abnormality is detected by the detector. The authenticator authenticates a provider of the charger. The connector-locking mechanism unlocks the connector when the provider is authenticated.
