Design or analysis of advanced power systems, involves knowledge in many disciplines. This paper introduces the virtual test bed (VTB) computational environment for modeling, dynamic simulation and virtual-prototyping of such interdisciplinary systems. A basic feature of the VTB is that it allows experts to build models within their domain of expertise using tools with which they are familiar, then to execute those models in a system context. We describe here several studies which illustrate how VTB can be used in the study of systems containing electrochemical power sources. The multiple approaches to construct models and the capabilities to co-simulate with other software packages are also described.