Cranking capability estimation for a vehicular starting system

A method of determining a cranking capability of a starting system, the method comprising the steps of:

• (a) detecting an ignition start operation;
• (b) determining a temperature of the starting system at the initiation of the ignition start;
• (c) measuring a battery voltage and a current during a predetermined interval of the ignition start;
• (d) determining an actual average power output value of the battery during the predetermined interval;
• (e) determining an average power output capability for a battery having a full state of charge at the determined temperature;
• (f) determining a minimum average power output value required of the battery for starting the respective engine at the determined temperature;
• and
• (g) calculating a state of function value of the starting system as a function of the average power output values determined in steps (d), (e), and (f).

A starting performance indication system for a vehicle starting system, the vehicle starting system including an internal combustion engine, a cranking device for cranking the internal combustion engine, a coupling device for mechanically coupling the cranking device to the internal combustion engine, and an energy storage device for supplying power to the cranking device for energizing the cranking device, the starting performance indication system comprising:

• at least one sensing device for determining a temperature of at least the energy storage device, the cranking device, and engine oil in the engine;
• a voltage sensing device for sensing the voltage output from the energy storage device;
• a current sensing device for sensing the current drawn by the cranking device;
• a control module having a starting system monitoring and prognosis routine for determining a state of function of the starting system, wherein the control module determines an average power output of the battery during the predetermined interval during engine cranking, an average power output for a battery having a full state of charge for starting the internal combustion engine at the determined temperature, and a minimum average power output value required of the battery for starting the internal combustion engine at the determined temperature;
• wherein the control module estimates the cranking capability of the starting system as function of the average power output of the battery during the predetermined interval during engine cranking, as a function of the average power output for a battery having a full state of charge, and as a function of the minimum average power output value required of the battery for starting the internal combustion engine.