Active metal-zinc pieces were used as an anode, and ammonium chloride was used as an electrolyte in an anode zone, with acids and soluble oxidant-bichromate as an active cathode substance and electrolyte in a cathode zone in a zinc-bichromate battery. Carbon felt was used as an inert cathode, with a PE-01 homogeneous membrane between the anode and cathode zones as well as 50 mL of solution in both the anode and cathode zones. The discharge characteristics of the batteries at 5 Omega were investigated for various pure acids, mixed acids, various concentrations of bichromate in the cathode zone and ammonium chloride in the anode zone. The output voltages of the batteries generally exceeded 1.70 V at the beginning of discharge, and the discharge time was more than 10 It. The discharge time and output voltage of the battery increase with the augment of concentrations of hydrogen ions in the cathode zone and the decrease of solid products formed at the carbon felt or membrane. When the concentrations of sodium bichromate were smaller than 0.75 M, hardly any solid products formed at the carbon felt or membrane. The actual gravimetric energy density of the batteries with 0.75 M ammonium bichromate, 1.8 M sulfuric acid, and 4.8 M hydrochloric acid in the cathode zone and 5 M ammonium chloride in the anode zone arrived at 51.93 W h kg(-1).