Battery temperature control method and battery temperature control device

A battery temperature control method in which a controller executes a temperature control of a chargeable/dischargeable battery installed in an electric vehicle, the battery temperature control method comprising:

• acquiring battery information including a temperature of the battery, a current temperature of the battery and a heat capacity of the battery;
• predicting a scheduled time at which the temperature of the battery will be within a desired temperature range, or acquiring information pertaining to the scheduled time;
• calculating a heating temperature, which is a temperature difference between a target temperature included in the desired temperature range and the current temperature of the battery;
• calculating an internal resistance of the battery based on the current temperature of the battery and the state of charge of the battery;
• predicting a charge/discharge current flowing through the internal resistance during execution of a heating control for raising the temperature of the battery;
• calculating a heating time of the heating control for the temperature of the battery to reach the target temperature based on the heating temperature, the heat capacity, the internal resistance, and the charge/discharge current;
• and
• executing the heating control to raise the temperature of the battery to the desired temperature range by the scheduled time by repeating a charge/discharge control of the battery prior to the scheduled time where the temperature of the battery is below the desired temperature range;