Abstract: A computer system includes processing circuitry configured to simulate, using electrical multi-battery models, the performance of a propulsion electrical energy storage system of a vehicle based on logged vehicle routes of the vehicle, the electrical energy storage system comprising multiple electrical energy storage packs, predict a lifetime of the electrical energy storage system based on the simulated performance of the propulsion electrical energy storage system and extrapolating forward assuming a worst-case aging rate; if the predicted lifetime exceeds a predetermined lifetime, indicate that an electrical energy storage pack downgrade replacement is required, and reduce a state of charge window of the electrical energy storage system at a rate such that a predetermined minimum state of charge window is not reached before a planned electrical energy storage pack downgrade replacement.