A power distribution system for a portable electronic device, the power distribution system comprising: a first voltage rail to provide operating voltage for basic functions of the electronic device; a second voltage rail to provide operating voltage for high power functions of the electronic device; a primary battery coupled in a selectable manner to the first voltage rail and the second voltage rail; a secondary battery coupled in a selectable manner to the first voltage rail and the second voltage rail; a selection architecture coupled to the first voltage rail, the second voltage rail, the primary battery, and the secondary battery; and a control module to regulate operation of the selection architecture in accordance with: a first power phase during which the primary battery is coupled to the first voltage rail and to the second voltage rail to provide energy for the basic functions and the high power functions; a second power phase during which the primary battery is coupled to the first voltage rail to provide energy for the basic functions, and during which the secondary battery is coupled to the second voltage rail to provide energy for the high power functions; and a third power phase during which the secondary battery is coupled to the first voltage rail and to the second voltage rail to provide energy for the basic functions and the high power functions. a first voltage rail to provide operating voltage for basic functions of the electronic device; a second voltage rail to provide operating voltage for high power functions of the electronic device; a primary battery coupled in a selectable manner to the first voltage rail and the second voltage rail; a secondary battery coupled in a selectable manner to the first voltage rail and the second voltage rail; a selection architecture coupled to the first voltage rail, the second voltage rail, the primary battery, and the secondary battery; and a control module to regulate operation of the selection architecture in accordance with: a first power phase during which the primary battery is coupled to the first voltage rail and to the second voltage rail to provide energy for the basic functions and the high power functions; a second power phase during which the primary battery is coupled to the first voltage rail to provide energy for the basic functions, and during which the secondary battery is coupled to the second voltage rail to provide energy for the high power functions; and a third power phase during which the secondary battery is coupled to the first voltage rail and to the second voltage rail to provide energy for the basic functions and the high power functions. a first power phase during which the primary battery is coupled to the first voltage rail and to the second voltage rail to provide energy for the basic functions and the high power functions; a second power phase during which the primary battery is coupled to the first voltage rail to provide energy for the basic functions, and during which the secondary battery is coupled to the second voltage rail to provide energy for the high power functions; and a third power phase during which the secondary battery is coupled to the first voltage rail and to the second voltage rail to provide energy for the basic functions and the high power functions.