A charging module to charge portable electric energy storage devices, the charging module comprising: a housing dimensioned to accommodate the at least partial insertion of a portable energy storage device along a longitudinal axis of the housing into an interior space formed by a peripheral housing wall joined to a base; a number of electric contacts (254, 256) projecting from the base at least partially into the interior space of the housing; a locking mechanism projecting from the base at least partially into the interior space of the housing; an entrance joined to the peripheral housing wall opposite the base, the entrance including an orifice connecting the interior space of the housing to an exterior space about the housing, the perimeter of the orifice closely corresponding to at least one physical aspect of the portable energy storage device casing; a housing door operably coupled to and positioned in the interior of the housing, the housing door axially displaceable along the longitudinal axis of the housing from a first position perpendicular to the housing wall and proximate the orifice to at least a second position perpendicular to the housing wall and proximate the base of the housing; an aperture concentric with the longitudinal axis of the housing through the housing door, the aperture to accommodate the passage of at least a portion of the locking mechanism and at least a portion of the number of electric contacts (254, 256) when the housing door is displaced to the second position; and at least one biasing element operably coupling the door to the base, the at least one biasing element biasing the housing door towards the first position. a housing dimensioned to accommodate the at least partial insertion of a portable energy storage device along a longitudinal axis of the housing into an interior space formed by a peripheral housing wall joined to a base; a number of electric contacts (254, 256) projecting from the base at least partially into the interior space of the housing; a locking mechanism projecting from the base at least partially into the interior space of the housing; an entrance joined to the peripheral housing wall opposite the base, the entrance including an orifice connecting the interior space of the housing to an exterior space about the housing, the perimeter of the orifice closely corresponding to at least one physical aspect of the portable energy storage device casing; a housing door operably coupled to and positioned in the interior of the housing, the housing door axially displaceable along the longitudinal axis of the housing from a first position perpendicular to the housing wall and proximate the orifice to at least a second position perpendicular to the housing wall and proximate the base of the housing; an aperture concentric with the longitudinal axis of the housing through the housing door, the aperture to accommodate the passage of at least a portion of the locking mechanism and at least a portion of the number of electric contacts (254, 256) when the housing door is displaced to the second position; and at least one biasing element operably coupling the door to the base, the at least one biasing element biasing the housing door towards the first position.