The electrochemical properties of LaNi3.55Mn0.4Al0.3Co0.4Fe0.35 hydrogen storage alloy have been studied through chronopotentiometric, chronoamperometric and cyclic voltammogram measurements. The maximum capacity value obtained was 265 mAh g(-1) at rate C/6 and the capacity decrease was recorded by 1.5% after 30 cycles. The values of the hydrogen diffusion coefficient DH obtained through cyclic volammogram and chronoamperometric techniques were, respectively, 7.01 X 10(-8) cm(2) s(-1) and 4.23 x 10(-11) cm(2) s(-1). (c) 2006 Elsevier B.V. All rights reserved.