An apparatus and method for a portable device incorporating a battery and a battery charger. In the portable device, there are a plurality of system components configured to facilitate a plurality of functions that the portable device is designed to perform. The battery in the portable device is configured for providing an internal power supply to the plurality of system components in the absence of an external input power supply. The battery charger is configured for charging the battery when the external input power supply is available. The battery charger disclosed herein is capable of supplying system power to the system components when voltage of the battery that is being charged is below a limit, thereby allowing the portable device to operate when voltage of the battery drops below the limit.