An electronic device includes two batteries and a main body. The main body defines a sliding groove passing through two parallel surfaces of the main body. The sliding groove includes an upper surface, a lower surface parallel to the upper surface, a positive contact plate and a negative contact plate. The positive contact plate is positioned on the upper surface. The negative contact plate is positioned on the lower surface. During replacement of the battery, each positive power supply plate of the two batteries remaining in contact with the positive contact plate, and each negative power supply plate of the two batteries remaining in contact with the negative contact plate.