Patent attributes
System are described that include an energy storage device adapted to store and release energy and an ultracapacitor. The systems include a switching device coupled to the energy storage device to selectively connect and disconnect the energy storage device to a load, and a second switching device coupled to the ultracapacitor and adapted to connect and disconnect the ultracapacitor to the load. The systems may include a sensor adapted to sense the current draw at the load. The first switching device is activated to connect the energy storage device to the load when a rate of change of the current draw at the load is below a threshold, and the second switching device is activated to connect the ultracapacitor to the load when the rate of change of the current draw at the load is greater than or equal to the threshold.