To provide a storage battery capable of save the trouble for charging, immediately using by only replacing an electrolyte, and quickly and easily replacing the electrolyte, and provide a charging method.

This charging device 3 is used for charging a storage battery 1 in which at least a pair of electrode plates is put in a container 5 containing an electrolyte, and a pouring opening 6 for pouring the electrolyte and an exhausting opening 7 for exhausting the electrolyte are installed in the container 5, and has a pressure vessel 21 having the electrolyte and compressed gas 24 on the inside; and a first piping member 22 having a first pouring nozzle 22a in which one end is inserted into the lower part of the pressure vessel 21 and other end is connected to the pouring opening 6 of the container 5 of the storage battery is installed, and when the first nozzle 22a is connected to the pouring opening 6 of the storage battery and a first selector valve 26 is operated to turn on, the electrolyte in the pressure vessel 21 is poured into the container 5 of the storage battery.