Abstract: A portable game machine having a high-power, short-life first power supply, and having a low-power long-life second power supply, each being configured for activating a game drive circuit that activates a game, and a game control circuit for issuing a control signal for activating the game. An on/off power switch connects the first power supply to the game drive circuit. A power management system controls power supply channels from the first and second power supplies. The power management system performing a plurality of functions, including supplying power to the game drive circuit and the game control circuit from the first power supply when the first power supply has sufficient power, and supplementally supplying power from the second power supply. The power management system may also control power supplied to the game control circuit and the game drive circuit based upon power levels in the first and second power supply.