Rechargeable battery pack for supplying electrical energy to hand-held power tools, preferably electrically powered gardening and/or forestry tools, wherein the rechargeable battery pack is configured for selective use in a vertical, preferably worn on the back, use position or a horizontal, preferably docked on a tool, use position and comprises the following: - an external housing which comprises a housing base and a housing hood connected to the housing base and which surrounds an interior space, and - a rechargeable battery cell block which is arranged in the interior space, characterized by - a water discharge structure for discharging at least one of water contained in the interior space and water which enters the external housing from outside, wherein - the water discharge structure comprises, on at least one side (1a, 1b) of the external housing, a double-labyrinth wall structure which is open to liquid and has an outer labyrinth wall structure, which is formed by overlapping of an outer side wall of the housing base and an outer side wall of the housing hood, and an inner labyrinth wall structure, which is arranged offset in relation to the outer labyrinth wall structure in a direction facing the interior space and which is formed by overlapping of an inner side wall of the housing base and an inner side wall of the housing hood, respectively, and/or - the water discharge structure comprises a labyrinth wall structure which is open to liquid and, in the vertical or the horizontal use position (V, H) of the rechargeable battery pack, is formed, in a manner leading in a direction downwards and to the outside, between an electrical plug-in connection body, which is arranged on the side of the housing base, and a corresponding tool connection plug in a plugged-in position. - an external housing which comprises a housing base and a housing hood connected to the housing base and which surrounds an interior space, and - a rechargeable battery cell block which is arranged in the interior space, - a water discharge structure for discharging at least one of water contained in the interior space and water which enters the external housing from outside, wherein - the water discharge structure comprises, on at least one side (1a, 1b) of the external housing, a double-labyrinth wall structure which is open to liquid and has an outer labyrinth wall structure, which is formed by overlapping of an outer side wall of the housing base and an outer side wall of the housing hood, and an inner labyrinth wall structure, which is arranged offset in relation to the outer labyrinth wall structure in a direction facing the interior space and which is formed by overlapping of an inner side wall of the housing base and an inner side wall of the housing hood, respectively, and/or - the water discharge structure comprises a labyrinth wall structure which is open to liquid and, in the vertical or the horizontal use position (V, H) of the rechargeable battery pack, is formed, in a manner leading in a direction downwards and to the outside, between an electrical plug-in connection body, which is arranged on the side of the housing base, and a corresponding tool connection plug in a plugged-in position.