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 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 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 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 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. <EOS>