A method for server-side characterization of a rechargeable battery (91-96) comprises obtaining operating values for a capacity of the battery (91-96) and an impedance (91-96) of the battery; based on the operating values: performing at least one state prediction (181-183) for the battery (91-96), each of the at least one state predictions (181-183) comprising a plurality of iterations (1099), wherein in each iteration (1099) a simulation of an electrical state of the battery (91-96) and a thermal state of the battery (91-96) is performed and an aging estimate for the capacity and the impedance is determined based on the results, wherein the aging estimate from a first iteration (1099) of the respective state prediction (181-183) is used for the simulation in a subsequent second iteration (1099) of the respective state prediction (181-183).