ENERGY STORAGE SYSTEM AND ENERGY STORAGE BANK INPUTTING METHOD

An energy storage system includes a plurality of energy storage banks connected in parallel to a trunk line, and a system management device. When a maximum voltage difference between the energy storage banks is equal to or greater than a first threshold before the energy storage banks are caused to input to the trunk line, the system management device executes a process of mitigating a cross current generated between the energy storage banks to mitigate a cross current accompanying the inputting to the trunk line by the energy storage banks. When the maximum voltage difference between the energy storage banks is less than the first threshold, the system management device causes the energy storage banks to input to the trunk line without limitation of the process of mitigating the cross current.