In this presentation, MathWorks engineers will present a process for developing lithium battery models for system level simulation and Battery Management System design. In this process, a battery cell model is built based on the electrochemical and thermal fingerprints of the battery. Nonlinearities are captured using look-up tables in Simscape™. Simulink Design Optimization™ is used to automate the parameterization process. As a result, simulation results are fitted to experimental discharge data. The model is then extended to a battery pack, taking advantage of the modularity of Simscape and the semiconductor element blocks in SimElectronics for external circuitry such as those for cell balancing. Finally, the model is optimized for speed which is essential for system level optimization and hardware in-the-loop testing.