A portable power supply device for an electric tool comprises: a power supply receiving portion, provided in or on a housing and used to receive a power supply supplying power to the electric tool, and a control unit, comprising a controller that is provided in the housing and is used to control the electric energy supplied to the electric tool. The power supply receiving portion comprises a power supply compartment, which is at least partially defined by a cover which can move relative to the housing between an opened position and a closed position. The power supply device further comprises a positioning accessory detachably and replaceably attached to the housing and/or the power supply receiving portion.