A processor-implemented method includes performing first parameter optimization of a battery model through a first predetermined optimization technique; switching, based on a count accumulated while performing the first parameter optimization indicating that a switching criterion has been met, from the first optimization technique to a second predetermined optimization technique; performing second parameter optimization of the battery model through the second predetermined optimization technique; and determining a final parameter combination as an optimized parameter of the battery model, in response to an occurrence of an optimization end event during the performance of the second parameter optimization.