A battery module array, comprising: a plurality of battery modules, each including two secondary battery cells, a module frame, and a cooling fin; end plates located at both side surfaces of a battery module assembly in which the plurality of battery modules are assembled; a tension bar in '[' shape contacting an upper end of the battery module assembly and fixed to the end plates; a front sensing unit including sensing bus bars electrically connected to electrode leads of the battery modules included in the battery module assembly, a terminal bus bar, a connector connectible with an external device and a housing, the front sensing unit being located at a front portion of the battery module assembly; a rear sensing unit including sensing bus bars electrically connected to the electrode leads of the battery modules included in the battery module assembly, a connector connectible with an external device and a housing, the rear sensing unit being located at a rear portion of the battery module assembly; at least one under-base bar located at a lower end of the battery module assembly and fixed to the end plates; characterized in that the battery module array further comprises: a front cover disposed and coupled at a front portion of the battery module assembly, configured to keep the front portion of the battery module assembly from being exposed to outside and including a first connector exposure groove allowing the connector of the front sensing unit to be exposed therethrough; and a rear cover disposed and coupled at a rear portion of the battery module assembly, configured to keep the rear portion of the battery module assembly from being exposed to outside and including a second connector exposure groove allowing the connector of the rear sensing unit to be exposed therethrough. a plurality of battery modules, each including two secondary battery cells, a module frame, and a cooling fin; end plates located at both side surfaces of a battery module assembly in which the plurality of battery modules are assembled; a tension bar in '[' shape contacting an upper end of the battery module assembly and fixed to the end plates; a front sensing unit including sensing bus bars electrically connected to electrode leads of the battery modules included in the battery module assembly, a terminal bus bar, a connector connectible with an external device and a housing, the front sensing unit being located at a front portion of the battery module assembly; a rear sensing unit including sensing bus bars electrically connected to the electrode leads of the battery modules included in the battery module assembly, a connector connectible with an external device and a housing, the rear sensing unit being located at a rear portion of the battery module assembly; at least one under-base bar located at a lower end of the battery module assembly and fixed to the end plates; characterized in that the battery module array further comprises: a front cover disposed and coupled at a front portion of the battery module assembly, configured to keep the front portion of the battery module assembly from being exposed to outside and including a first connector exposure groove allowing the connector of the front sensing unit to be exposed therethrough; and a rear cover disposed and coupled at a rear portion of the battery module assembly, configured to keep the rear portion of the battery module assembly from being exposed to outside and including a second connector exposure groove allowing the connector of the rear sensing unit to be exposed therethrough. a front cover disposed and coupled at a front portion of the battery module assembly, configured to keep the front portion of the battery module assembly from being exposed to outside and including a first connector exposure groove allowing the connector of the front sensing unit to be exposed therethrough; and a rear cover disposed and coupled at a rear portion of the battery module assembly, configured to keep the rear portion of the battery module assembly from being exposed to outside and including a second connector exposure groove allowing the connector of the rear sensing unit to be exposed therethrough.