The device's efficiency -- defined as the ratio of output power to input power -- varied depending on the voltage, load on the device, and the degree of degradation of the tape on the commutator of the device. If the device simply transferred the power from the batteries to the load, its efficiency would be 100 percent; in no case did the device's efficiency approach 100 percent.

At all conditions tested, the input Power exceeded the output power. That is, the device did not deliver more energy than it used.