An energy transfer apparatus includes a cable having first end with a first connector operably coupled thereto and a second end with a second connector operably coupled thereto. The energy transfer apparatus also includes a control unit coupled to the cable. The control unit includes a device interface module configured to determine a first energy parameter of a first portable device connected to the cable via the first connector and to determine a second energy parameter of a second portable device connected to the cable via the second connector. The control unit also includes an energy transfer module configured to facilitate energy transfer between the first and second portable devices based on the first and second energy parameters.