A current detection device includes a current sensor and a controller. The current sensor outputs a detection voltage according to a conduction current flowing through a bi-directional circuit in which current is capable of flowing in a positive direction and a negative direction that is a direction opposite to the positive direction. The controller calculates the conduction current based on the detection voltage output from the current sensor. For example, the controller calculates the conduction current based on an absolute value of a difference between a reference voltage that is the detection voltage output during a non-conductive state in which current is not flowing through the bi-directional circuit, and the detection voltage output during a conductive state in which current is flowing through the bi-directional circuit.