A method of managing an energy storage system of a vehicle, wherein said vehicle is a part of a vehicle fleet being in communication with a central unit, said energy storage system having a beginning of life, said vehicle having at least a first application and a second application, said energy storage system having a first end of life (EOL 1) for said first application and a second end of life (EOL 2) for said second application, said ESS having a first lifetime between said BOL and said EOL 1 and a second lifetime between said BOL and said EOL 2, said method comprising the steps of: a) determining energy and/or power requirement for said vehicle being in said first application; b) defining energy and/or power of said energy storage system at the beginning of life of said energy storage system of said vehicle; c) determining a first state of health value SOH 1 at the first end of life (EOL 1) of said energy storage system of said vehicle being in said first application; d) determining energy and/or power requirement for said vehicle being in said second application; e) determining a second state of health value SOH 2 at the second end of life (EOL 2) of said energy storage system if said vehicle is used in said second application f) communicating said SOH 1 and/or said SOH 2 of said ESS to said central unit; the method characterised in that it further comprises: g) identifying a vehicle group within said vehicle fleet, wherein the ESS of the vehicles in said vehicle group are approaching EOL; h) suggesting said at least first or second application for each vehicle in said vehicle group such that said lifetime of said energy storage system of each vehicle within said vehicle group is maximized by choosing the application giving the highest SOH value. a) determining energy and/or power requirement for said vehicle being in said first application; b) defining energy and/or power of said energy storage system at the beginning of life of said energy storage system of said vehicle; c) determining a first state of health value SOH 1 at the first end of life (EOL 1) of said energy storage system of said vehicle being in said first application; d) determining energy and/or power requirement for said vehicle being in said second application; e) determining a second state of health value SOH 2 at the second end of life (EOL 2) of said energy storage system if said vehicle is used in said second application f) communicating said SOH 1 and/or said SOH 2 of said ESS to said central unit; the method characterised in that it further comprises: g) identifying a vehicle group within said vehicle fleet, wherein the ESS of the vehicles in said vehicle group are approaching EOL; h) suggesting said at least first or second application for each vehicle in said vehicle group such that said lifetime of said energy storage system of each vehicle within said vehicle group is maximized by choosing the application giving the highest SOH value. g) identifying a vehicle group within said vehicle fleet, wherein the ESS of the vehicles in said vehicle group are approaching EOL; h) suggesting said at least first or second application for each vehicle in said vehicle group such that said lifetime of said energy storage system of each vehicle within said vehicle group is maximized by choosing the application giving the highest SOH value.