A method is provided for determining a cranking capability of a starting system for an internal combustion engine. An average power output of a battery is determined for the starting system during a start engine cranking interval. A temperature of the starting system is determined at an initiation of the start engine cranking interval. A predetermined average power output capability for a battery having a full state of charge at the determined temperature is looked up. A predetermined minimum average power output required of the battery for starting the respective engine at the determined temperature is looked up. A state of function based on the determined average power outputs is determined. The cranking capability of the starting system is identified in response to the determined state of function.