NOVELTY - Controlling the temperature of an electrical energy storage system (ESS) (401) coupled to electric power train of electric vehicle involves determining whether or not power source external to electric vehicle is connected to ESS charging system; and if not determining a current ESS temperature with at least one temperature sensor, comparing current ESS temperature with preset temperature, activating ESS cooling system if current ESS temperature is greater than preset temperature, and deactivating ESS cooling system if current ESS temperature is lower than preset temperature.    USE - Method for controlling the temperature of an electrical energy storage system coupled to electric power train of an electric vehicle.    ADVANTAGE - The battery pack of electric vehicle is actively cooled after the vehicle has been turned off, thus limiting the adverse effects of temperature on battery life. Different battery pack cooling techniques are provided, thus allowing the cooling technique used in a particular instance to be selected not only based on the thermal needs of the battery pack, but also on the thermal capacity and energy requirements of the selected approach.    DETAILED DESCRIPTION - Controlling the temperature of an ESS (401) coupled to electric power train of electric vehicle, comprises:    (A) monitoring an operational condition of electric vehicle, where the operational condition is either in a first state of operation or a second state of operation, where the first state of operation corresponds to electric vehicle being turned on, and where the second state of operation corresponds to electric vehicle being turned off;    (B) determining whether or not a power source external to the electric vehicle is connected to an ESS charging system; and    (C) if the power source is not connected to the ESS charging system and if the electric vehicle is in the second state of operation, the method further comprises determining a current ESS temperature with at least one temperature sensor; comparing the current ESS temperature with a preset temperature; activating an ESS cooling system if the current ESS temperature is greater than the preset temperature; deactivating the ESS cooling system if the current ESS temperature is lower than the preset temperature; and repeating step (C) until the current ESS temperature is lower than the preset temperature.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic view of an ESS cooling system.    ESS (401)    Dryer (515)    Reservoir (521)    Heater (523)    Thermal management system (600)    Radiator (601)