Patent ID: 8106534

Claim:
A powering subassembly for a portable electronic device, comprising: a main battery to provide a main voltage to the portable electronic device; a backup battery to provide a backup voltage to the portable electronic device; a capacitor coupled to and charged by the backup battery to receive the backup voltage and to transfer the received voltage; a converter to receive the voltage transferred from the capacitor and to generate at least one operating voltage; and a controller to receive the at least one operating voltage from the converter, to monitor the main voltage of the main battery, to compare the monitored level of the main battery to a main battery low voltage threshold, and if the monitored level of the main battery is less than or equal to the main battery low voltage threshold, to transmit a disconnect signal to disconnect the main battery and transmit a connect signal to couple the backup voltage from the backup battery to the capacitor, wherein said voltage transferred from the capacitor to the converter is sufficient to handle peak loads that cannot be handled directly by the backup battery.