Zinc Carbon Batteries have zinc as anode (negative terminal) and carbon as the cathode (positive terminal).
We can use exhausted dry cell battery by taking the carbon rods out and mount above glass water tight cells into make batteries again. The mixture for the electrolyte to be used is:
7 ounces of bichromate of sodium dissolved in one quart of water.
Next, we add very slowly a half a pint of strong sulfuric acid and stirring this mixture slowly with a glass rod all the while. After this mixture is cool poor it into a glass battery jar and add one ounce bisulphate of mercury which will amalgamate (alloy a metal with mercury) and keep amalgamated the zinc cylinder. The solution should be sufficient quantity to extend up the zinc cylinder for 3/4 of its height. When batteries are not used, take rod mounts out of the liquid solution.
For Safety,
If working with batteries and any of this acid or solution does get on the hands or clothes rinse off immediately with clean water.
