NOVELTY - The method involves providing a main energy manager (22) to activate energy management functions when a state variable (24) having a setting state, and a parameter reaches a corresponding main limiting value and/or meets a corresponding main condition. An emergency energy manager (26) is provided to activate the functions when the state variable having a basic state, and the parameter reaches a corresponding predetermined emergency limiting value and/or meets a corresponding emergency condition. The emergency limiting value is higher than the main limiting value.    USE - Method for activating energy management functions depending on a current state of a battery in a motor vehicle e.g. battery-operated hybrid vehicle, fuel cell vehicle and electric car. Uses include but are not limited to a start-stop function, an intelligent alternator regulation, a recuperation function and an acceleration assistance function.    ADVANTAGE - The method enables providing the emergency energy manager to activate the energy management functions when the state variable having the basic state, and the parameter reaches the corresponding predetermined emergency limiting value and/or meets the corresponding emergency condition such that the energy management functions can be activated in quick and reliable manner.    DETAILED DESCRIPTION - The energy management functions are selected from a group consisting of a start-stop function (12.1), an intelligent alternator regulation (12.2), a recuperation function (12.3) and an acceleration assistance function (12.4). INDEPENDENT CLAIMS are also included for the following:    (1) a device for activating an energy management function in a vehicle depending on a current state of a battery    (2) a computer program product comprising a program code for performing a method for activating an energy management function in a vehicle depending on a current state of a battery    (3) a data processing program comprising a set of instructions executing a method for activating an energy management function in a vehicle depending on a current state of a battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of an energy management function activation arrangement in a vehicle.    Start-stop function (12.1)    Intelligent alternator regulation (12.2)    Recuperation function (12.3)    Acceleration assistance function (12.4)    Main energy manager (22)    State variable (24)    Emergency energy manager (26)