The charger 10 includes a first charging path that charges battery banks via current limiting resistors R1 to R3, a second charging path that charges the battery banks without passing through the current limiting resistors R1 to R3, and a circuit that is capable of selectively switching the first and second charging paths to one another, being provided to the respective battery banks, and being identical in resistance values of the current limiting resistors R1 to R3. A battery voltage detection circuit detects the voltages of the battery banks; and a controller 16 controls the first to third charging circuits so that the battery banks are charged through the first charging path when there is difference in the voltages of the battery banks. The battery banks are charged through the second charging path when there is no difference in the voltages of the battery banks.