Method and apparatus for managing alternator loads on engines

DETAILED DESCRIPTION The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 1.
A method of managing loads on an engine equipped with a chargeable battery that has a voltage level which varies during its use, and an alternator-type battery charging system that has field windings which must be electrically excited to produce electricity and includes a voltage regulator adapted to shut down the alternator electrical generation functions by turning off a field excitation circuit which provides electrical current to the alternator field windings when a normal threshold battery voltage level is reached, comprising the steps of: establishing a proportional charging range between an alternative minimum battery voltage threshold below which it is undesirable to allow the battery to discharge and an alternator disabling threshold battery voltage level, said alternator disabling threshold being a battery voltage level that is more than said alternate minimum battery voltage level and less than said normal threshold level; sensing the load condition of the engine; proportionally disabling the field when the battery voltage level is within said proportional charging range and the engine is under heavy load in such a manner that the alternator electrical generation increases as the battery voltage level decreases toward said alternate minimum battery voltage threshold and decreases as the battery voltage increases toward said alternator disabling threshold; switching the field excitation circuit continuously off when the engine is under heavy load and the battery voltage level is above said alternator disabling threshold; switching said field excitation circuit essentially continuously on when the battery voltage level discharges below said alternate minimum battery voltage; switching said field excitation circuit to essentially normal operation, as controlled by the voltage regulator, when the engine is not heavily loaded, wherein said switching of said field excitation circuit to normal operation is ramped to allow for gradual return of alternator electrical generation functions should the battery voltage level be below said normal threshold battery voltage level