Battery device

A battery device comprising:

• a battery;
• a circuit substrate electrically connected to the battery;
• a switch configured to control input and output of electric power to and from the battery, the switch being arranged in the battery device such that an empty space gap is present between the switch and the circuit substrate, and the switch is not in direct physical contact with the circuit substrate;
• and
• a heat radiator made of a material having thermal conductivity and being in contact directly or indirectly through a heat conductor with an exterior part of the switch so that heat of the switch transfers to the heat radiator, wherein
• the switch includes a signal line transmitting an electric signal, and a power line transmitting electric power, and
• the power line is connected to an input-output terminal of the battery without the power line being connected to the circuit substrate,
• the power line is connected to the input-output terminal through a bus bar or a harness, and
• the signal line is connected to the circuit substrate.

A battery device comprising:

• a battery;
• a circuit substrate electrically connected to the battery;
• a switch configured to control input and output of electric power to and from the battery, and having an exterior part forming an outer surface of the switch and being away from the circuit substrate, such that an empty space gap is present between the switch and the circuit substrate, and the switch is not in direct physical contact with the circuit substrate;
• and
• a heat radiator made of a material having thermal conductivity and being in contact directly or indirectly through a heat conductor with the exterior part of the switch so that heat of the switch transfers to the heat radiator, wherein
• the switch and the heat radiator are positioned below and away from the circuit substrate.