A power system having an extended life and a system and method for extending the life of a battery powered device. In one embodiment, the method comprises providing a plurality of power sources and an alternate energy source. The method also comprises measuring the voltage of the power sources and the alternate energy source. The method further comprises selecting a power source to provide voltage to the device, wherein the selected power source provides voltage to the device. In addition, the method comprises optionally charging any power source that is providing voltage to the device. Moreover, the method is repeated after a variable delay. Further embodiments include switching to providing the voltage to the device from a power source while charging another power source.