Battery temperature adjustment system

A battery temperature adjustment system includes: a battery configured to store electric power from an external power source, and supply electric power to a motor as a drive source of a vehicle; a cooling device to which the electric power from the external power source and the electric power from the battery are selectively supplied and configured to cool the battery; and a control device configured to control the cooling device to lower a temperature of the battery to a target cooling temperature while the vehicle is stopped. The target cooling temperature is a variable value. The control device obtains a target set by a user, and sets the target cooling temperature based on the target.