Printing device including battery tray attachable to battery accommodating portion of housing and having mounting surface configured to support battery

A battery unit attachable to a printing device comprising a printing engine configured to be driven by electric power supplied from a battery and to perform printing on a printing medium,

• the battery unit comprising:
• a unit housing comprising a plurality of walls defining a space serving as a battery accommodating portion configured to accommodate therein the battery, the battery accommodating portion being open in a first direction orthogonal to an up-down direction, the plurality of walls comprising an upper wall formed with an opening that is open downward;
• a contact terminal electrically connected to the printing engine in a state where the battery unit is attached to the printing device, the contact terminal facing downward and being exposed to the battery accommodating portion through the opening formed in the upper wall, the contact terminal flexing upward in a state where the contact terminal is in contact with a battery terminal provided on an upper surface of the battery accommodated in the battery accommodating portion;
• and
• a battery tray having a mounting surface on which the battery is configured to be mounted from above, the battery tray being attachable to the battery accommodating portion in a second direction opposite the first direction,
• wherein, in a state where the battery is mounted on the mounting surface, the mounting surface supports the battery such that the battery is movable on the mounting surface between:
• a first position, the battery at the first position being placed in a first posture;
• and
• a second position, the battery at the second position being placed in a second posture,
• wherein the battery at the second position is positioned further in the second direction relative to the battery at the first position,
• wherein the battery terminal on the battery in the second posture is positioned further downward relative to the battery terminal on the battery in the first posture,
• wherein the plurality of walls further comprises a pressing portion, and
• wherein, during an attachment process of the battery tray to the battery accommodating portion, the pressing portion presses the battery at the second position in the first direction to move the battery to the first position and place the battery in the first posture such that the battery terminal contacts the contact terminal from below.