A software algorithm (FIG. 3) determines the strategy by which a controller (34) will manage state of charge (SOC) of a battery pack (32) in a hybrid electric vehicle but always gives the driver the opportunity to make his/her own selection instead. The algorithm causes one of two strategies to be selected each time that the ignition switch is operated from “off” position to “on” position. The manner in which the algorithm executes depends on the value of a calibratable parameter electronically programmed into the controller of the particular vehicle when the vehicle is being built at the factory.