Provided is an electrical connection box including a housing casing for housing a relay, and a heat transfer sheet for transferring heat from the relay to the housing casing, the electrical connection box including: a bus bar provided between a top surface and an inside surface that correspond to each other in the housing casing so as to oppose the top surface and the inside surface; a first holding portion protruding from the inside surface and holding the bus bar via the heat transfer sheet; and a second holding portion protruding from the top surface and holding the bus bar.

An electromagnetic relay includes a housing, a first fixed terminal, a movable contact piece, a drive device, and a first heat dissipation member. The first fixed terminal protrudes from inside the housing to outside the housing. The movable contact piece is disposed in the housing. The movable contact piece faces the first fixed terminal. The drive device moves the movable contact piece in a contact direction and an opening direction. The first heat dissipation member is disposed outside the housing. The first heat dissipation member is provided separately from the first fixed terminal. The first heat dissipation member is connected to the first fixed terminal.

An electromagnetic relay includes a housing, a first fixed terminal, a movable contact piece, a drive device, and a first heat dissipation member. The first fixed terminal protrudes from inside the housing to outside the housing. The movable contact piece is disposed in the housing. The movable contact piece faces the first fixed terminal. The drive device moves the movable contact piece in a contact direction and an opening direction. The first heat dissipation member is disposed outside the housing. The first heat dissipation member is provided separately from the first fixed terminal. The first heat dissipation member is connected to the first fixed terminal.

A battery distribution unit includes a housing having a bottom mounted to a battery case of a battery module and having a component cavity with a contactor therein. The contactor has fixed contacts having terminating ends extending from a bottom end of a contactor housing. The BDU includes terminals at the bottom end of the contactor coupled to the terminating ends and a heat exchanger cap at the bottom end of the contactor. The heat exchanger cap is provided in the component cavity in thermal communication with the fixed contacts and in thermal communication with the battery case of the battery module to dissipate heat from the fixed contacts into the battery case of the battery module.

A battery distribution unit includes a housing having a bottom mounted to a battery case of a battery module and having a component cavity with a contactor therein. The contactor has fixed contacts having terminating ends extending from a bottom end of a contactor housing. The BDU includes terminals at the bottom end of the contactor coupled to the terminating ends and a heat exchanger cap at the bottom end of the contactor. The heat exchanger cap is provided in the component cavity in thermal communication with the fixed contacts and in thermal communication with the battery case of the battery module to dissipate heat from the fixed contacts into the battery case of the battery module.

Provided is a circuit assembly including: a main relay that is to be electrically connected between a load and a battery; a pre-charge circuit connected in parallel with the main relay; and a heat transfer member, wherein the pre-charge circuit includes current-carrying portions that are to be connected to the main relay, and the heat transfer member and the current-carrying portions are in contact with each other.

Provided is a circuit assembly including: a main relay that is to be electrically connected between a load and a battery; a pre-charge circuit connected in parallel with the main relay; and a heat transfer member, wherein the pre-charge circuit includes current-carrying portions that are to be connected to the main relay, and the heat transfer member and the current-carrying portions are in contact with each other.

A power relay assembly is provided. A power relay assembly according to an exemplary embodiment of the present invention comprises: a support plate having at least one electric element mounted on one surface thereof and including a plastic material having heat dissipation and insulation properties; and at least one bus bar electrically connected to the electric element and partially embedded in the support plate. Due to these features, since heat generated from the bus bar and the electric element is dissipated to the outside through the support plate, it is possible to prevent performance deterioration due to heat and breakage of electronic components.

A power relay assembly is provided. A power relay assembly according to an exemplary embodiment of the present invention comprises: a support plate having at least one electric element mounted on one surface thereof and including a plastic material having heat dissipation and insulation properties; and at least one bus bar electrically connected to the electric element and partially embedded in the support plate. Due to these features, since heat generated from the bus bar and the electric element is dissipated to the outside through the support plate, it is possible to prevent performance deterioration due to heat and breakage of electronic components.

A control unit includes: an input portion that receives the positional information of a vehicle; a calculation unit that generates a control signal for controlling an electromagnetic relay; and an output portion that outputs the control signal to the electromagnetic relay. The calculation unit determines whether a location region of the electromagnetic relay is a relay-freeze region, the location region being identified by the positional information of the vehicle, and, when the location region of the electromagnetic relay is a relay-freeze region, performs a freeze inhibiting process for preventing the electromagnetic relay from being frozen or defrosting the electromagnetic relay by opening and closing the electromagnetic relay and causing the electromagnetic relay to vibrate.