This paper presents a heat transfer fin optimization for a LaNi(5) hydrogen storage container. In this simplified approach, a one-dimension fin model is proposed in order to avoid geometrical restrictions and constrains associated to a particular technological solution. Therefore, the presented model can be utilized as a general framework for the development of containers with inner fins. The hydrogen absorption reaction was simulated using a developed finite difference method. On this base, the heat transfer fin design was optimized for different absorption times and container diameters applying the gradient method. Numerical outcomes were then confirmed by comparison with experimental measurements, showing good agreement between the theoretical model and the experimental result. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.