Power storage system and method for controlling the same

A power storage system comprising:

• a battery containing an electrolytic solution;
• and
• a control device that controls, based on a temperature of said battery, permission and prohibition of charge/discharge of said battery,
• said control device being configured to:
• set a first determination temperature equal to or higher than a freezing point of said electrolytic solution and a second determination temperature higher than said first determination temperature, said first determination temperature being set based on a relation between the freezing point of said electrolytic solution and a degree of deterioration of said battery;
• and
• prohibit charge/discharge of said battery when the temperature of said battery falls below said first determination temperature while said electrolytic solution is in a liquid state, and cancel the prohibition of charge/discharge of said battery when said electrolytic solution turns into the liquid state from a state in which said electrolytic solution is at least partially solidified, and when the temperature of said battery exceeds said second determination temperature.