A control module is arranged in alignment with a battery module in a longitudinal direction. The control module includes a busbar, a switch and a current sensor configured to detect electric current flowing through the busbar. The current sensor includes a magneto-electric transducer and a magnetic field suppressor. The magneto-electric transducer is configured to convert a magnetic field, which depends on the electric current flowing through the busbar and passes through the magneto-electric transducer along a plane perpendicular to a height direction, into an electrical signal. The magnetic field suppressor is configured to suppress external magnetic fields from passing through the magneto-electric transducer along the plane perpendicular to the height direction. The switch includes a pair of magnets that are magnetized and opposed to each other in a lateral direction perpendicular to both the longitudinal and height directions. The current sensor is aligned with the magnets in the longitudinal direction.