Patent attributes
A powering subassembly for a portable electronic device includes a main battery, a converter, a backup battery, and a controller. The main battery provides a main voltage and the backup battery can provide a backup voltage. The converter receives the main voltage and increases the main voltage to at least one operating voltage. The controller receives the operating voltage from the converter, monitors the voltage of the main battery, and compares the monitored main battery voltage to a main battery low voltage threshold. The controller transmits a disconnect signal to decouple the main battery from the converter if the monitored voltage from the main battery is less than the main battery low voltage threshold. The controller transmits a connection signal to couple the backup battery to the converter if the monitored voltage is less than the main battery low voltage threshold. The backup battery provides the power for a predetermined minimum amount of time.