Eveready heavy duty batteries are leak-proof guaranteed as per the IEC standard service tests, and their liability is only limited to the replacement of the batteries. Eveready Heavy Duty Red batteries have an anode of zinc, a cathode of manganese dioxide, and a slightly acidic electrolyte. Zinc carbon batteries work due to an electrochemical reaction within the cell. The ability of zinc-carbon batteries to function in any orientation helped in the development of various portable devices like flashlights and radios.