A battery carrier configured to be mounted to a tool body of an electric tool for supplying electric power to the tool body is provided. The battery carrier may include a plurality of battery mount sections disposed at a first surface of the battery carrier and each configured to hold a battery, a tool body mount section disposed at a second surface of the battery carrier opposite to the first surface and configured to be mounted to the tool body, and a marker disposed at the first surface and serving as a target for movement of the tool body mount section relative to the tool body when the tool body mount section is mounted to the tool body.