A power tool battery pack receptacle includes a cavity in which a portion of a battery pack is receivable, an insertion end, a closed end opposite the insertion end along an insertion axis of the battery pack, and a rail extending between the insertion end and the closed end. The rail includes a first portion having a variable height and a second portion having a substantially constant height. The first portion is positioned adjacent the insertion end and the second portion is spaced from the insertion end. The rail is configured to be received within a groove of the battery pack.