A system for managing storage or delivery of electrical energy. The system includes a plurality of stackable energy storage devices, one or more connectors, a plurality of switches, and a controller. The stackable energy storage devices receive the electrical energy from at least one external device or provide the electrical energy to the at least one external device. Each connector connects to a plug of a cable extending from an external device and provides a connection between an energy storage device and the external device. The switches are disposed between the energy storage devices and the one or more connectors and open or close the connection between the energy storage device and the external device. The controller controls the switches to open or close the connection. The system includes a user interface for receiving user input, and the controller controls the switch based on the user input.