Our previous paper  has described an unconventional chemically regenerative redox fuel cell, including a modest amount of performance data, and has pointed out a number of problem areas. This paper describes additional work and some attempts that have been made to improve the cell performance in several of the problem areas described in the first paper. Two different redox fuel cell systems employing the V2+/V3+ and Mo3+Mo4+ redox couples as the anolyte, and a new NO3−/NO catalyst system for VO2+ oxidation were explored and described. The reduction of Na2MoO4 to Mo4+ and Mo3+ by H2 in concentrated H2SO4 solution was studied in small scale laboratory experiments and discussed. The performance of a redox cell in which H2 was obtained from the Pd-catalysed decomposition of formic acid, HCOOH, is described and the results of experiments with different membranes are reported. The results of experiments using WC as a hydrogenation catalyst at a temperature of 70–90° C with mixed molybdo-tungsto-silicic acids are reported and discussed.