The characteristics of rapid gaseous H(2) charging/electrochemical discharging of the metal hydride negative electrode were investigated for the application in Fuel Cell/Battery (FCB) systems. They were evaluated with the H(2) gas absorption, followed by the subsequent electrochemical discharging in the electrolyte solution (6M KOH). Then, the cyclability of charge-discharge was also examined. it was observed that more than 70% of the theoretical capacity was charged within 10 min with 0.3 MPa and 0.5 MPa of the initial H(2) pressures. The electrochemical discharge curve showed that more than 86% of the absorbed H(2) was discharged. Furthermore, the cycled charge-discharge process indicated that the H(2) gas charge and electrochemical discharge process is an effective way to rapidly charge and activate the metal hydride without degeneration. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.