The effect of chemical composition of some fuel compounds: sodium tetrahydridoborate, boron hydride dimethylamine, lithium aluminium hydride, hydrazine, ethanolamine, ethanol and ethylenediamine, on the electrical response of a laboratorial membrane fuel cell have been studied in alkaline medium. The self-discharge, current-voltage and power curves have shown that the response of fuel cell is strongly dependent of electrode kinetics related with the reducing agents in-situ. The best performance was obtained with NaBH4, displaying the cell a maximum power of 31.28 mW at 68.6 mA current.