Abstract: A selector switch for switching a connection state between a first power source and a second power source into series connection or parallel connection, includes a fixed conductive unit provided with a series-use breaking point and a parallel-use breaking point, and a movable connection unit including a series-use terminal and a parallel-use terminal, wherein when the movable connection unit is positioned at a first position, the parallel-use breaking point remains disconnected, and the series-use breaking point is connected to be in a conductive state, whereby the first power source and the second power source are connected in series, and when the movable connection unit is positioned at a second position, the series-use breaking point remains disconnected, and the parallel-use breaking point is connected to be in a conductive state, thereby connecting the first power source and the second power source in parallel.

Abstract: A connection structure of a plurality relays and busbars, wherein the relays include: a first relay for switching a first circuit as a predetermined electrical circuit between a powered and a non-powered states; and a second relay for switching a second circuit, which is different from the first circuit, as a predetermined electrical circuit between a powered and a non-powered states, the first and second circuits being configured to be supplied with power in the powered state and to be supplied with no power in the non-powered state. The busbars include: a first busbar connected to the first relay to form the first circuit; and a second busbar connected to the second relay to form the second circuit. The first busbar and the second busbar are connected for releasing heat, wherein the second busbar is in the non-powered state in the powered state of the first circuit.