Abstract: The invention is directed to techniques for testing a powerability characteristic of a backup power supply for a computerized device using a discharge circuit that is different than circuitry of the computerized device. The discharge circuit is capable of draining float charge of the backup power supply thus enabling a measuring circuit to properly determine whether the backup power supply is suitable for providing the operating power to the computerized device for the predetermined amount of time in the event the computerized device no longer receives main power from the main power supply. One arrangement of the invention is directed to a computer system that includes a computerized device, a main power supply that provides power to the computerized device, a backup power supply coupled to the main power supply to receive charge from the main power supply.