Traduzione in corso passo 6
Use the skin of the peeled bat to fully bond them.
Cover the notches and wires with some tape. Shown PI/Kapton tape will be the best choice, anything thin enough and isolate is ok.
The skin is a little short for 2 cells. The exposed metal should be covered also. They are the positive terminal. You don't wanna short-circuit something, do you? (not yet covered in these photos)