Abstract: The invention relates to a method for determining the remaining run time (?ti) of a battery (4) that is supplying power to an appliance (2). The method comprises the steps of: —during operation of the appliance (2) measuring the voltage (Ui) supplied by the battery (4) at different points in time (ti) in order to obtain time-voltage-pairs (t,U,), and—calculating the remaining run time (?ti) of the battery (4), wherein the calculation is based on the measured time-voltage-pairs (ti, Ui) and on a relationship between the measured voltage (Ui), the corresponding point in time (ti) and the total run time (T1) of the battery (4) which can be derived from a time dependent formulation of the Nernst equation for this relationship.

Abstract: The invention relates to a method for determining the remaining run time (?ti) of a battery (4) that is supplying power to an appliance (2). The method comprises the steps of: during operation of the appliance (2) measuring the voltage (Ui) supplied by the battery (4) at different points in time (ti) in order to obtain time-voltage-pairs (ti, Ui), and-calculating the remaining run time (?t) of the battery (4), wherein the calculation is based on the measured time-voltage-pairs (ti, Ui) and on a relationship between the measured voltage (Ui), the corresponding point in time (ti) and the total run time (T1) of the battery (4) which can be derived from a time dependent formulation of the Nernst equation for this relationship.