A fuel cell (FC) using liquid fuel and oxidizer is under investigation. H 2 O 2 is used in this FC directly at the cathode. Either of two types of reactant, namely a gas-phase hydrogen or an aqueous NaBH 4 solution, are utilized as fuel at the anode. Experiments demonstrate that the direct utilization of H 2 O 2 and NaBH 4 at the electrodes results in >30% higher voltage output compared to the ordinary H 2 /O 2 FC. Further, the use of this combination of all liquid fuels, provides numerous advantages (ease of storage, reduced pumping requirements, simplified heat removal, etc.) from an operational point of view. This design is inherently compact compared to other cells that use gas phase reactants. Further, regeneration is possible using an electrical input, e.g. from power lines or a solar panel. While the peroxide-based FC is ideally suited for applications such as space power where air is not available and a high energy density fuel is essential, other distributed and mobile power uses are of interest.