In a method for determining the state of function SOF of an energy storage battery,
in particular a starter battery for a motor vehicle, as the capability to supply
at least one load with an amount of energy, by determining a characteristic value
for the state of charge SOC of the energy storage battery and a characteristic
value for the state of health SOH when an electrical load is applied to the energy
storage battery, with state of health (SOH) being the suitability of the energy
storage battery to emit a specific amount of energy to the at least one load while
maintaining a minimum voltage, a characteristic value for the state of function
(SOF) is determined by linking the characteristic values for the state of charge
(SOC) and for the state of health (SOH).
