That's enough. Remove the zinc skin from the used battery and wash it. Zinc and copper are respectively connected with wires, but do not touch each other. They can be used to make batteries after being soaked in salt water. The voltage is approximately 1 volt
Negative electrode: 2Zn -4e- = 2Zn2+, positive electrode: O2 + 2H2O +4e- = 4OH-