A method for predicting service life of a battery unit previously used within at least one first application, the method comprising: - assessing a battery capacity of the battery unit at an end of a first service life of the battery unit within the at least one first application, - identifying a suitable second application for the battery unit by comparing the assessed battery capacity to given power requirements of at least one suggested second application, - obtaining ageing data indicative of battery ageing of the battery unit in its at least one first application, - predicting an expected second service life of the battery unit in the identified second application based on at least information relating to a planned usage of the battery unit in the second application and on the obtained ageing data from the at least one first application, wherein predicting the expected second service life of the battery unit comprises: ∘ creating (S4-1) a set of battery usage classifications, ∘ for each battery usage classification, determining (S4-2) at least one expected ageing curve (1a, 1b, 1c; 2a, 2b, 2c) associated with that battery usage classification, ∘ classifying (S4-3) the planned usage of the battery unit in accordance with the set of battery usage classifications, wherein the prediction of the expected second service life is determined based on the at least one expected ageing curve (1a, 1b, 1c; 2a, 2b, 2c) of the battery usage classification associated with the classified planned usage, the method further comprising: - during usage of the battery unit in the identified second application, obtaining operational data relating to an actual usage of the battery unit, - predicting an actual second service life of the battery unit in the second application based on at least the obtained operational data by classifying the actual usage of the battery unit in accordance with the set of battery usage classifications, - comparing the predicted actual second service life with the predicted expected second service life, thus obtaining a comparison result, - determining whether a predetermined notification criterion is fulfilled based on the comparison result, - generating a notification to a user of the battery unit if the predetermined notification criterion is fulfilled. - assessing a battery capacity of the battery unit at an end of a first service life of the battery unit within the at least one first application, - identifying a suitable second application for the battery unit by comparing the assessed battery capacity to given power requirements of at least one suggested second application, - obtaining ageing data indicative of battery ageing of the battery unit in its at least one first application, - predicting an expected second service life of the battery unit in the identified second application based on at least information relating to a planned usage of the battery unit in the second application and on the obtained ageing data from the at least one first application, wherein predicting the expected second service life of the battery unit comprises: ∘ creating (S4-1) a set of battery usage classifications, ∘ for each battery usage classification, determining (S4-2) at least one expected ageing curve (1a, 1b, 1c; 2a, 2b, 2c) associated with that battery usage classification, ∘ classifying (S4-3) the planned usage of the battery unit in accordance with the set of battery usage classifications, wherein the prediction of the expected second service life is determined based on the at least one expected ageing curve (1a, 1b, 1c; 2a, 2b, 2c) of the battery usage classification associated with the classified planned usage, ∘ creating (S4-1) a set of battery usage classifications, ∘ for each battery usage classification, determining (S4-2) at least one expected ageing curve (1a, 1b, 1c; 2a, 2b, 2c) associated with that battery usage classification, ∘ classifying (S4-3) the planned usage of the battery unit in accordance with the set of battery usage classifications, - during usage of the battery unit in the identified second application, obtaining operational data relating to an actual usage of the battery unit, - predicting an actual second service life of the battery unit in the second application based on at least the obtained operational data by classifying the actual usage of the battery unit in accordance with the set of battery usage classifications, - comparing the predicted actual second service life with the predicted expected second service life, thus obtaining a comparison result, - determining whether a predetermined notification criterion is fulfilled based on the comparison result, - generating a notification to a user of the battery unit if the predetermined notification criterion is fulfilled.