A dynamic model of a discrete reversible fuel cell (RFC) system has been developed in a Matlab Simulink (R) environment. The model incorporates first principles dynamic component models of a proton exchange membrane (PEM) fuel cell, a PEM electrolyzer, a metal hydride hydrogen storage tank, and a cooling system radiator, as well as empirical models of balance of plant components. Dynamic simulations show unique charging and discharging control issues and highlight factors contributing to overall system efficiency. (C) 2008 Elsevier B.V. All rights reserved.