Abstract: The embodiments herein provide an energy storage battery system constituting multiple banks of individual batteries, each of which may have different characteristics, and methods of operation of the system. The multiple battery banks configuration is based on split battery configuration derived by a splitter based on a probability distribution function (pdf) of expected usage pattern, optimization goal, and battery characteristics of a corresponding single battery system. The energy system optimizes at least one of cost, weight or size of the overall system by rotating usage of various battery banks based on usage pattern.