Metal hydrides can store hydrogen at low pressures with high volumetric capacity. These features make metal hydrides particulalry good candidates for safe storage of hydrogen in stationary applications. This paper compares the hydrogen charging and discharging times of three different metal hydride reactors with different geometry of the heat exchangers. The simplest reactor was a cylindrical reactor made of stainless steel with no internal heat exchanger, and heat transfer through the external walls. The second reactor was made from aluminium and had a replaceable heat exchanger. Two types of heat exchangers were tested; a brush type of heat exchanger and a tube type. The third reactor was also made of aluminium and had an internal heat exchanger consisting of a tube with radial fins. The reactors were filled with 0.85-2.5 kg of AB5 type metal hydride powder. Charging and discharging experiments with different charging and discharging pressure and different heating and cooling water temperatures were performed. A total energy balance for the different units was also performed, and the results were used to calculate the heat duty per unit driving force. The experiments performed indicate that the product of the overall heat transfer number and heat transfer surface together with the ambient hydrogen charging or discharging pressure are the parameters affecting the charging and discharging time the most.