Procedure for the computer-aided determination of the theoretically remaining service life of an exchangeable battery, wherein in a pipe distribution network (10, 200) for the supply of water or gas, and/or for the removal of process water, which has a hierarchical structure of branches of pipes (12-82; 206-254, 270), several branches of pipes are each fitted with at least one flowmeter designed as a stand-alone device, wherein said branches are connected in a master/slave network and communicate wirelessly with one another, wherein, in the pipe network, at least one flowmeter is designed as the master flowmeter (52; M) in a hierarchically higher-level pipe branch, and wherein several other flowmeters in a hierarchically lower-level pipe branch are designed as slave flowmeters that report the measured values they measure to the master flowmeter (52; M), wherein at least the slave flowmeters are supplied with energy in each case by an individual battery that is assigned to the slave flowmeter and connected to said flowmeter, and wherein the procedure is carried out for at least one of the slave flowmeters in the pipe network and comprises the following steps which are carried out by a computer that is integrated in a communication and supply unit of the affected slave flowmeter and that is connected to said flowmeter: • Definition of a matrix of influencing factors that affect a theoretical service life of a battery, wherein a voltage drop per time that is measured in the battery is considered as an influencing factor and wherein the influencing factors constitute, in particular, the switch-on frequency of the slave flowmeter concerned, its measuring cycle, its operating time, and the pressure and temperature of the environment; • Computer-controlled recording of the influencing factors - starting from the installation of the battery through to the battery's failure or end of life - at defined times depending on an operating time of the slave flowmeter in question that had elapsed by this point in time; • Determination by the computer of the theoretical service life with the variation of various influencing factors with the help of the matrix taking into account all influencing factors recorded up until now and the operating time that has elapsed; • Wherein the voltage drop per time that is currently measured is compared against a theoretically calculated value for the relevant configuration of the slave flowmeter and wherein an alarm signal is generated if a predefined deviation is exceeded; and • wherein - if the value drops below a predefined remaining theoretical service life - a signal is generated that indicates that the battery needs to be replaced. • Definition of a matrix of influencing factors that affect a theoretical service life of a battery, wherein a voltage drop per time that is measured in the battery is considered as an influencing factor and wherein the influencing factors constitute, in particular, the switch-on frequency of the slave flowmeter concerned, its measuring cycle, its operating time, and the pressure and temperature of the environment; • Computer-controlled recording of the influencing factors - starting from the installation of the battery through to the battery's failure or end of life - at defined times depending on an operating time of the slave flowmeter in question that had elapsed by this point in time; • Determination by the computer of the theoretical service life with the variation of various influencing factors with the help of the matrix taking into account all influencing factors recorded up until now and the operating time that has elapsed; • Wherein the voltage drop per time that is currently measured is compared against a theoretically calculated value for the relevant configuration of the slave flowmeter and wherein an alarm signal is generated if a predefined deviation is exceeded; and • wherein - if the value drops below a predefined remaining theoretical service life - a signal is generated that indicates that the battery needs to be replaced.