An energy storage system, comprising: an energy storage module adapted to supply electrical energy to a hybrid or electric vehicle, the energy storage module comprising: a primary enclosure; a battery array located within the primary enclosure, the battery array having a plurality of battery cells; a plurality of high voltage connection terminals, the high voltage connection terminals adapted to receive a corresponding plurality of external high voltage conductors; a high-voltage junction box mounted outside of the primary enclosure; and a plug-in bussed electrical center located within the high-voltage junction box and comprising: a modular removable connector formed of electrically insulative material having a plurality of internal terminal connectors (3312, 3314) and a plurality of external terminal connectors (3316, 3318); wherein the plurality of external terminal connectors are configured to physically connect to one or more corresponding external terminals in the high-voltage junction box that are electrically connected to the battery array of the energy storage module; wherein the plurality of internal terminal connectors (3312, 3314) are configured to contact one or more corresponding internal terminals of the high-voltage junction box to complete a circuit between the internal and external terminals of the high-voltage junction box when the modular removable connector is inserted, and to break the circuit between the internal and external terminals of the high-voltage junction box when the modular removable connector is removed; wherein the internal terminal connectors (3312, 3314) and the external terminal connectors (3316, 3318) rigidly extend away from the modular removable connector to physically interact with the internal and external connectors of the high-voltage junction box; wherein the plug-in bussed electrical center is operable to electrically connect at least one of the plurality of high voltage connection terminals of the energy storage module to the battery array to provide power to the plurality of external high voltage conductors. a primary enclosure; a battery array located within the primary enclosure, the battery array having a plurality of battery cells; a plurality of high voltage connection terminals, the high voltage connection terminals adapted to receive a corresponding plurality of external high voltage conductors; a high-voltage junction box mounted outside of the primary enclosure; and a plug-in bussed electrical center located within the high-voltage junction box and comprising: a modular removable connector formed of electrically insulative material having a plurality of internal terminal connectors (3312, 3314) and a plurality of external terminal connectors (3316, 3318); wherein the plurality of external terminal connectors are configured to physically connect to one or more corresponding external terminals in the high-voltage junction box that are electrically connected to the battery array of the energy storage module; wherein the plurality of internal terminal connectors (3312, 3314) are configured to contact one or more corresponding internal terminals of the high-voltage junction box to complete a circuit between the internal and external terminals of the high-voltage junction box when the modular removable connector is inserted, and to break the circuit between the internal and external terminals of the high-voltage junction box when the modular removable connector is removed; wherein the internal terminal connectors (3312, 3314) and the external terminal connectors (3316, 3318) rigidly extend away from the modular removable connector to physically interact with the internal and external connectors of the high-voltage junction box; wherein the plug-in bussed electrical center is operable to electrically connect at least one of the plurality of high voltage connection terminals of the energy storage module to the battery array to provide power to the plurality of external high voltage conductors. a modular removable connector formed of electrically insulative material having a plurality of internal terminal connectors (3312, 3314) and a plurality of external terminal connectors (3316, 3318); wherein the plurality of external terminal connectors are configured to physically connect to one or more corresponding external terminals in the high-voltage junction box that are electrically connected to the battery array of the energy storage module; wherein the plurality of internal terminal connectors (3312, 3314) are configured to contact one or more corresponding internal terminals of the high-voltage junction box to complete a circuit between the internal and external terminals of the high-voltage junction box when the modular removable connector is inserted, and to break the circuit between the internal and external terminals of the high-voltage junction box when the modular removable connector is removed; wherein the internal terminal connectors (3312, 3314) and the external terminal connectors (3316, 3318) rigidly extend away from the modular removable connector to physically interact with the internal and external connectors of the high-voltage junction box; wherein the plug-in bussed electrical center is operable to electrically connect at least one of the plurality of high voltage connection terminals of the energy storage module to the battery array to provide power to the plurality of external high voltage conductors.