Apparatus comprising at least one electrolytic capacitor (1,1a,1b) and a device to estimate the lifetime consumption of the at least one electrolytic capacitor (1,1a,1b), characterized by the device comprising a) a temperature sensor which is thermally insulated from the ambient by being arranged i) either between two equal electrolytic capacitors (1a,1b) connected in parallel with each other or ii) on a case of the at least one electrolytic capacitor (1,1a,1b) and covered with a layer of thermally insulating material, and b) a controller which is suitable to estimate the lifetime consumption based on the measurement data of the temperature sensor, wherein the apparatus allows the user to specify a usage cycle which is expected to be repeated in the future and wherein the controller determines the lifetime consumption and preferably its uncertainty either in time segments or continuously during the usage cycle, and wherein the controller determines the usage cycle lifetime consumption by integrating the continuously determined lifetime consumptions over the usage cycle or by adding the lifetime consumption of all time segments of the usage cycle and determines preferably the uncertainty of the usage cycle lifetime consumption, wherein the usage cycle lifetime consumption is used by the controller to determine a preliminary predicted lifetime (54a,b) by extrapolating the total lifetime consumption (LC total (t), 45) linearly, wherein the preliminary predicted lifetime (L pp, 54a,b) is the duration between the beginning of the life of the capacitor and the time at which the extrapolation of the total lifetime consumption (LC total (t), 45) reaches a value which indicates the end of the lifetime, wherein the controller comprises in addition preferably a clock counting an age of the one or more electrolytic capacitors (1,1a,1b), wherein the residual lifetime is estimated by the controller to be the smaller one of the following two numbers: i) the preliminary predicted lifetime (54a,b) minus the current age of the one or more electrolytic capacitors (1,1a,1b) ii) the maximum age of the one or more electrolytic capacitors (1,1a,1b) minus the current age of the one or more electrolytic capacitors (1,1a,1b) and wherein the residual lifetime is preferably returned together with its uncertainty. the lifetime consumption of the at least one electrolytic capacitor (1,1a,1b), characterized by the device comprising a) a temperature sensor which is thermally insulated from the ambient by being arranged i) either between two equal electrolytic capacitors (1a,1b) connected in parallel with each other or ii) on a case of the at least one electrolytic capacitor (1,1a,1b) and covered with a layer of thermally insulating material, and b) a controller which is suitable to estimate the lifetime consumption based on the measurement data of the temperature sensor, a) a temperature sensor which is thermally insulated from the ambient by being arranged i) either between two equal electrolytic capacitors (1a,1b) connected in parallel with each other or ii) on a case of the at least one electrolytic capacitor (1,1a,1b) and covered with a layer of thermally insulating material, and i) either between two equal electrolytic capacitors (1a,1b) connected in parallel with each other or ii) on a case of the at least one electrolytic capacitor (1,1a,1b) and covered with a layer of thermally insulating material, and b) a controller which is suitable to estimate the lifetime consumption based on the measurement data of the temperature sensor, wherein the apparatus allows the user to specify a usage cycle which is expected to be repeated in the future and wherein the controller determines the lifetime consumption and preferably its uncertainty either in time segments or continuously during the usage cycle, and wherein the controller determines the usage cycle lifetime consumption by integrating the continuously determined lifetime consumptions over the usage cycle or by adding the lifetime consumption of all time segments of the usage cycle and determines preferably the uncertainty of the usage cycle lifetime consumption, wherein the usage cycle lifetime consumption is used by the controller to determine a preliminary predicted lifetime (54a,b) by extrapolating the total lifetime consumption (LC total (t), 45) linearly, wherein the preliminary predicted lifetime (L pp, 54a,b) is the duration between the beginning of the life of the capacitor and the time at which the extrapolation of the total lifetime consumption (LC total (t), 45) reaches a value which indicates the end of the lifetime, wherein the controller comprises in addition preferably a clock counting an age of the one or more electrolytic capacitors (1,1a,1b), wherein the residual lifetime is estimated by the controller to be the smaller one of the following two numbers: i) the preliminary predicted lifetime (54a,b) minus the current age of the one or more electrolytic capacitors (1,1a,1b) ii) the maximum age of the one or more electrolytic capacitors (1,1a,1b) minus the current age of the one or more electrolytic capacitors (1,1a,1b) i) the preliminary predicted lifetime (54a,b) minus the current age of the one or more electrolytic capacitors (1,1a,1b) ii) the maximum age of the one or more electrolytic capacitors (1,1a,1b) minus the current age of the one or more electrolytic capacitors (1,1a,1b) and wherein the residual lifetime is preferably returned together with its uncertainty.