you may have made batterys from coin.but there is a new way to make batttery.that is by using only a soda can (not empty)and a nail.want to know how?see the full instruction.it is great for class projects.by the way this one cell produces 0.76 volts.so i used a joule thief to increase the volt to light a led.you can make a joule thief following this tutorialhttps://www.instructables.com/id/make-a-joule-thief-easily/

visit my profile:https://www.instructables.com/member/argha+halder/ to see some of such interesting projects.

Step 1: Ingredients

the things you need are:
1)a soda can (with soda)
2)a steel nail.or copper or brass or iron nail or piece
3)led light(for testing)
4)insulative tape
5)scissors

Step 2:

take the scissor and with its sharp end make a hole in the can.on the upper side .it should be big enough so that the nail can enter in it.

Step 3: Making the Cathode

now take a bit of insulative tape and stick it on the upper portion of the nail like in the photo.

Step 4: Making the Battery

now take the taped nail and insert it through the hole in the can so that the un taped part of nail is in the soda or just touching the soda and the taped part is attached or fitted with the can.

believe it or not the battery is ready!

Step 5: Testing It!

the nail head is the positive lead.and the uncoloured portion of the can is negative part.touch the voltmetres lead to the nail and the body or can and see the metre show electricity!

i just showed by touching the led.i did not use the joule thief when it is not lighted.

precaution:be extremely careful not to make hole in your own hand instead of the can!

Step 6: How Does It Work?

soda can is made of alluminium and soda is an electrolyte.and alluminim extracts negative charge and the the nail extracted positive charge from the soda and the battery worked

Step 7: Trouble Shooting

if your cell does not work check whether the nail is touching the can.if it is touching then use more insulative tape so that they dont touch each other. remember:you wont be able to light leds directly from it.if you want to light leds you have to make four to five of these.so dont blame me if the led does not light directly.