An automated storage and retrieval system comprising at least one container handling vehicle, a horizontal rail system for the container handling vehicle to run on, and a charging station for recharging a replaceable power supply of the container handling vehicle and an automated loader (40;40') arranged on the rail system, wherein: the container handling vehicle comprises a first set of wheels for moving the container handling vehicle upon the rail system in a first direction, a second set of wheels for moving the container handling vehicle upon the rail system in a second direction which is perpendicular to the first direction, and a power supply compartment within the container handling vehicle for accommodating a replaceable power supply when the container handling vehicle is in use; and the charging station is provided on or at the horizontal rail system, the charging station comprising one or more charging racks, each charging rack providing a column of charging positions at different levels for recharging replaceable power supplies and each charging position being configured to accommodate a replaceable power supply during a recharging process; wherein the automated loader (40; 40') comprises a first set of wheels for moving the automated loader upon the rail system in the first direction and a second set of wheels for moving the automated loader upon the rail system in the second direction, and wherein the automated loader (40;40') further comprises a power supply support for releasably supporting the replaceable power supply, wherein the power supply support comprises two laterally extending guide arms (43a,43b) by which the replaceable power supply may be supported, each guide arm comprising a tapered end extending beyond a section of the guide arms by which the power supply may be supported, wherein the power supply support is arranged to move vertically such that the horizontal movement of the automated loader (40;40') and the vertical movement of the power supply support enables exchanging and transporting a replaceable power supply between the charging rack and the power supply compartment of the container handling vehicle by retrieving a first replaceable power supply from the power supply compartment of the container handling vehicle and inserting the first replaceable power supply into any charging position of the charging rack and by retrieving a second replaceable power supply from the charging rack and inserting the second replaceable power supply into the power supply compartment of the container handling vehicle and by extending the power supply support of the automated loader (40; 40') into said charging rack and power supply compartment. the container handling vehicle comprises a first set of wheels for moving the container handling vehicle upon the rail system in a first direction, a second set of wheels for moving the container handling vehicle upon the rail system in a second direction which is perpendicular to the first direction, and a power supply compartment within the container handling vehicle for accommodating a replaceable power supply when the container handling vehicle is in use; and the charging station is provided on or at the horizontal rail system, the charging station comprising one or more charging racks, each charging rack providing a column of charging positions at different levels for recharging replaceable power supplies and each charging position being configured to accommodate a replaceable power supply during a recharging process; wherein the automated loader (40; 40') comprises a first set of wheels for moving the automated loader upon the rail system in the first direction and a second set of wheels for moving the automated loader upon the rail system in the second direction, and wherein the automated loader (40;40') further comprises a power supply support for releasably supporting the replaceable power supply, wherein the power supply support comprises two laterally extending guide arms (43a,43b) by which the replaceable power supply may be supported, each guide arm comprising a tapered end extending beyond a section of the guide arms by which the power supply may be supported, wherein the power supply support is arranged to move vertically such that the horizontal movement of the automated loader (40;40') and the vertical movement of the power supply support enables exchanging and transporting a replaceable power supply between the charging rack and the power supply compartment of the container handling vehicle by retrieving a first replaceable power supply from the power supply compartment of the container handling vehicle and inserting the first replaceable power supply into any charging position of the charging rack and by retrieving a second replaceable power supply from the charging rack and inserting the second replaceable power supply into the power supply compartment of the container handling vehicle and by extending the power supply support of the automated loader (40; 40') into said charging rack and power supply compartment.