An advanced one-dimensional, isothermal mathematical model for a single cell of an alkaline fuel cell (AFC) is presented. Advances in an expression for the volume average velocity and in correlations and parameters are achieved. The parameters and operating conditions of the model are based on the Obiter Fuel Cell, which is employed as a power source for NASA space shuttles. A stimulated result is obtained that shows a close agreement with some of the experimental data. Profiles of variables, local overpotential and local current density are also obtained as a function of cell voltage. An investigation of the influence of initial electrolyte concentration shows that the performance of the AFC is maximized at a concentration of 3.5 M. Finally, it is found that increasing the operating pressure steadily enhances cell performance.