Disconnect device

A disconnect device configured to operate together with a power storage element including a first electrode and a second electrode, the disconnect device comprising:

• a heatsink;
• a substrate having a first surface and a second surface opposite to the first surface and further having a first edge, a second edge, a third edge, and a fourth edge each connected to the first surface and the second surface, the first surface contacting the heatsink, the substrate including a first heat transfer part, a second heat transfer part, a third heat transfer part, a fourth heat transfer part, and a fifth heat transfer part which are provided along the second surface of the substrate;
• a first charging relay provided on the second surface of the substrate, the first charging relay contacting the first heat transfer part;
• a second charging relay provided on the second surface of the substrate, the second charging relay contacting the second heat transfer part;
• a first discharging relay provided on the second surface of the substrate, the first discharging relay contacting the third heat transfer part;
• a second discharging relay provided on the second surface of the substrate, the second discharging relay contacting the fourth heat transfer part;
• a first charging end and a second charging end which are led out from the first edge of the substrate;
• a first output end and a second output end which are led out from the second edge of the substrate, the first output end and a second output end being thermally coupled to the fifth heat transfer part;
• a first power storage end led out from the third edge or the fourth edge of the substrate, the first power storage end being configured to be connected to the first electrode of the power storage element;
• and
• a second power storage end led out from the third edge or the fourth edge of the substrate, the second power storage end being configured to be connected to the second electrode of the power storage element, wherein
• both the first discharging relay and the second discharging relay are disposed closer to the first power storage end and the second power storage end than both the first charging relay and the second charging relay are,
• the second edge of the substrate is positioned opposite to of the first edge of the substrate in a first direction,
• the first heat transfer part, the second heat transfer part, the third heat transfer part, and the fifth heat transfer part are arranged in the first direction,
• the fourth heat transfer part and the fifth heat transfer part are arranged in a second direction perpendicular to the first direction, and
• a heat dissipating performance of the heatsink on the third heat transfer part, the fourth heat transfer part, and the fifth heat transfer part of the substrate is higher than a heat dissipating performance of the heatsink on the first heat transfer part and the second heat transfer part of the substrate.