The novel vanadium bromide (V/Br) redox flow cell employs a vanadium(II)/vanadium(III) couple in the negative half-cell and a Br-/Br-3(-) couple in the positive half-cell, using a mixture of vanadium bromide, hydrobromic acid and hydrochloric acid as the electrolyte in both half-cells. An ion exchange membrane separates the two V/Br half-cell electrolytes. In this project, small test cell cycling experiments were conducted to evaluate the performance of a range of ion exchange membranes in the V/Br redox flow cell. The features and charge/discharge results of the V/Br redox flow cell will also be discussed in this paper. (c) 2005 Elsevier B.V. All rights reserved.