Battery mount device

A battery mount device comprising:

• a housing to which a battery pack is detachably attached;
• a cover attached to the housing so as to cover the battery pack and configured to open and close by rotating around a rotation axis;
• and
• a cover holding mechanism configured to hold the cover in an open state,
• wherein the cover holding mechanism includes a cover holder and a first biasing member,
• the cover holder is supported by the housing and configured to move relative to the housing,
• the cover holder is configured to move, in response to an operation by a user, between a holding position and a released position along a direction substantially parallel to the rotation axis of the cover,
• when the cover holder is in the holding position, the cover holder interferes with a rotating motion of the cover,
• when the cover holder is in the released position, the cover holder does not interfere with the rotating motion of the cover, and
• the first biasing member is configured to bias the cover holder from the holding position toward the released position.