That's enough. Remove the zinc skin from the used battery and wash it. Zinc and copper are connected with wires respectively, but do not touch each other. They can be used as batteries after being soaked in salt water. the voltage is approximately 1 volt.
Negative electrode: 2Zn -4e- = 2Zn2+, positive electrode: O2 + 2H2O +4e- = 4OH-
Simply make an electrolytic cell, find a container and fill it with diluted solution. hydrochloric acid or This may be diluted salt water. Simply use conductive wires to attach metals with different activities on both sides. . Typically, a block of copper is bonded on one side and a block of zinc on the other. Or you can attach a copper block to one side and an iron block to the other. . . Be careful, take it out and put it in water when not in use. . . Otherwise it will melt. .