Battery mounting unit, electric device, and power supply unit

A battery mounting unit configured to be attached to an apparatus that receives electric power from a battery device having an external terminal, the battery device being attachable and detachable to/from the battery mounting unit, the battery mounting unit comprising:

• a connection terminal configured to fit to the external terminal and having a shape along which the external terminal is slidable at least in one direction;
• and
• a lever rotatable about a fulcrum, the lever being located at a side at which the connection terminal is located when seen from the battery device in a state where the external terminal is fitted to the connection terminal, wherein
• one of the external terminal or the connection terminal is configured to be elastically deformable to allow the external terminal and the connection terminal to fit to each other by sandwiching the other one of the external terminal or the connection terminal between the one of the external terminal or the connection terminal,
• the lever includes
• an arm including the fulcrum and a first action part, the first action part being located closer to the battery device than the fulcrum in the state where the external terminal of the battery device is fitted to the connection terminal and being configured to contact the battery device when the lever rotates about the fulcrum, and
• a gripper connected to a side of the arm opposite to the first action part with respect to the fulcrum, and
• when the lever rotates about the fulcrum by a force applied to the gripper, the first action part applies a force to the battery device such that the battery device slides in a direction in which fitting between the external terminal and the connection terminal is canceled.