The present invention discloses a method for predicting the voltage of a
battery, in particular a vehicle battery. The method according to the
invention makes it possible to predict a voltage drop before it actually
occurs as a result of a load. For this purpose, a filtered battery
voltage and a filtered battery current are first of all determined from
battery data, such as the battery voltage, the battery current, the
battery temperature and the dynamic internal resistance. The resistive
voltage drop across the dynamic internal resistance is determined from
the difference current between the filtered battery current and the
predetermined load current. Furthermore, a polarization voltage is
calculated as a function of the filtered battery current, and is then
filtered. The predicted battery voltage is calculated from the filtered
battery voltage, minus the resistive voltage drop and the filtered
polarization voltage. A decision on further measures can be made on the
basis of this predicted battery voltage.