Abstract: A control circuit receives a starting signal from a powertrain control module of a vehicle and delays the coupling of the main starting current from the battery to the starting motor until a reduced current in an alternative flow path is provided to the starter motor, initiating its motion. In a preferred, the pre-start sequence is controlled by a microprocessor which provides a control signal to a solid state switch coupled by a conductor providing current limiting resistance between the battery supply and the starter motor for a predetermined period of time. Subsequent to the pre-spin period, the control circuit provides a signal to a different solid state switch which activates the starter solenoid, in turn, coupling the battery to the starter motor and engaging the pinion gear with the ring gear.

Abstract: A method for maximizing the availability of start-stop operations within a microhybrid vehicle includes determining the electric current drawn by a set of electrical components of the vehicle, from the vehicle's battery. The internal resistance of the vehicle's battery, and the resistance of a starter motor loop circuit coupled to the engine of the vehicle are dynamically calculated. The closed-circuit voltage of the battery is predicted, using the internal resistance of the battery, the resistance of the starter motor loop circuit, and the current drawn by the set of electrical components of the vehicle. The start-stop operation is carried out if the closed-circuit voltage of the battery is predicted to be above a pre-determined minimum value.

Abstract: A method for maximizing the availability of start-stop operations within a microhybrid vehicle includes determining the electric current drawn by a set of electrical components of the vehicle, from the vehicle's battery. The internal resistance of the vehicle's battery, and the resistance of a starter motor loop circuit coupled to the engine of the vehicle are dynamically calculated. The closed-circuit voltage of the battery is predicted, using the internal resistance of the battery, the resistance of the starter motor loop circuit, and the current drawn by the set of electrical components of the vehicle. The start-stop operation is carried out if the closed-circuit voltage of the battery is predicted to be above a pre-determined minimum value.

Abstract: A control circuit receives a starting signal from a powertrain control module of a vehicle and delays the coupling of the main starting current from the battery to the starting motor until a reduced current in an alternative flow path is provided to the starter motor, initiating its motion. In a preferred, the pre-start sequence is controlled by a microprocessor which provides a control signal to a solid state switch coupled by a conductor providing current limiting resistance between the battery supply and the starter motor for a predetermined period of time. Subsequent to the pre-spin period, the control circuit provides a signal to a different solid state switch which activates the starter solenoid, in turn, coupling the battery to the starter motor and engaging the pinion gear with the ring gear.