Optimization Methods to Plan the Charging of Electric Vehicle Fleets. Retrieved Feburary 20, 2013, from http://www.zurich.ibm.com/pdf/csc/EDISON ccpe main.pdf

Abstract—This paper describes an approach to optimize elec-tric vehicle battery charging behavior with the goal of minimizing charging costs, achieving satisfactory state-of-energy levels, and optimal power balancing. Two methods for charging schedule optimization are compared. The first formulation uses a linear approximation of the battery behavior, whereas the second uses a quadratic approximation. A non-linear and state-dependent battery model is used to evaluate the solutions of the two methods. Our results indicate that the linear approximation is sufficient when considering the electric vehicle charging plan optimization