We can find batteries all over our home, on cellphones, remotes, laptops and more; essentially batteries have chemicals that produce electrons through electrochemical reactions.



Every battery has 2 terminals, one marked with (+) being the positive terminal and one with (-) being the negative terminal.

Unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place. That is why a battery can sit on a shelf for a year and still have plenty of power.





How a chemical reaction makes electricity?





It’s very simple, you’ve probably heard about metal rusts if you leave it outdoors, that’s an oxidation chemical reaction, where the oxygen (O 2 ) “steals” electrons from metals forming oxides.

That reaction involves a movement of electrons and that’s the principle of batteries.

A common battery will have 3 main parts for it to work.

2 Different Metals (Copper and Zinc that are more common)

1 Electrolite (this is a solution saturated with ions)

On the electrochemical reaction the Zinc Terminal (Zn) loses electrons and flow through the wire to the Copper (Cu) terminal, the copper accepts the electrons.

While the reactions goes on the Zinc terminal will “dissolve” as it becomes oxidized to Zn2+ and the Copper terminal will get thicken from the Cu+2 ions on the solution reduce to Cu0 metallic state.

Home made batteries





Want to try yourself? Will give you 2 ways to make electricity





Materials





For the first one: Pennies, Nickels, Dimes, Salt, Wires and Paper Towels

And a Voltmeter or a LED





Mix salt with water (as much salt as the water will hold) and soak the paper towel in this brine. Then create a pile by alternating pennies and nickels. See what kind of voltage and current the pile produces. Try a different number of layers and see what effect it has on voltage. Then try alternating pennies and dimes and see what happens. Also try dimes and nickels.

Be careful when you try the led on this battery because it may burn the LED depending on how many coins you stacked.

Now the second





You will need potatoes or lemons, wire, a Copper and a Zinc foil or you can use pennies and nickels.

Get the potatoe and stab the copper and zinc bars, you just made a battery :), you can try the lemon and see which gives you more voltage.





There are 2 ways to connect batteries: Serial or Parallel

You can try to stack potatoes in Serial to get more voltage and make your cellphone work, but will you really go to the street and walk around with a sack of potates on your back?



