Abstract: Provided is a water addition plug for a storage battery, which is for carrying out water addition into a container of the storage battery. The water addition plug comprising a water addition plug main body having a water supply port through which the water is supplied, a water addition port through which the supplied water is discharged into the container, and a valve chest disposed between the water supply port and the water addition port and provided with a first valve and a second valve and a float that moves up and down following an electrolyte level in the container. The first valve comprises a first drain port, which is open to the valve chest and communicates with the water addition port, and a first valve element for closing the first drain port in synchronization with a vertical movement of the float. The second valve comprises a second drain port, which is open to the valve chest and communicates with the water addition port, and a second valve element for closing the second drain port.

Abstract: Provided is a water addition plug for a storage battery, which is for carrying out water addition into a container of the storage battery. The water addition plug comprising a water addition plug main body having a water supply port through which the water is supplied, a water addition port through which the supplied water is discharged into the container, and a valve chest disposed between the water supply port and the water addition port and provided with a first valve and a second valve and a float that moves up and down following an electrolyte level in the container. The first valve comprises a first drain port, which is open to the valve chest and communicates with the water addition port, and a first valve element for closing the first drain port in synchronization with a vertical movement of the float. The second valve comprises a second drain port, which is open to the valve chest and communicates with the water addition port, and a second valve element for closing the second drain port.