An agricultural baler includes a main bale chamber and a plunger reciprocally movable within the main bale chamber. The plunger has a duty cycle. A flywheel is associated with the movement of the plunger, and a driveline is associated with the flywheel and couplable with a power take-off of a traction unit. The baler is characterized by an auxiliary power system coupled with the driveline. The auxiliary power system includes a power indicator providing a plurality of output signals, each representing a parameter associated with power usage during the duty cycle of the plunger. A power device receives power from or transfers power to the driveline. An electrical processing circuit is coupled with the power indicator and the power device. The electrical processing circuit receives each output signal and controls operation of the power device, based on at least one output signal from at least one previous duty cycle.
