A cool project that will teach you how to formulate a battery through some spare  change. The complete project is fun and needs just a few steps. All you will need is a calculator, an LED bulb, sand paper, an electrolyte like salt water, lemon juice, or vinegar; scissors, cardboard, electrical tape, two or three LED bulbs, and zinc washers. The first thing you need to do is pick up your calculator and unscrew all its screws present on its rear end. Now reach out to the battery, remove it, and keep it aside for other projects. Pull out the positive and negative leads from the casing and attach the wires to the terminal if possible.You can also just twist the wires with battery leads and use the electrical tapes to keep all together. 

 

 

Now pick out three zinc washers and three pennies. Cut out three round pieces of cardboard in a manner that their edges are little bigger than that of pennies. Let these soak in vinegar for a moment or two. Now you can start building your battery cell by keeping a piece of aluminum foil over workspace. You  can now place a zinc washer on the other end. Now, take the cardboard piece that has been soaked in vinegar, let it blot dry with some paper towel and keep it on top of the washer. Finally, place the copper penny over the cardboard and your battery is done. 

 

Any individual battery cell has a zinc bottom and a copper top separated from each other by a paper-like material or some cardboard that has been soaked in electrolyte. As a common reading, every single cell gives out a voltage of 0.6 volts and power worth 700mA. The copper top acts as positive and zinc bottom as negative. A result calculator needs some 1.5-colts to work out, therefore, here you can use 3 pennies, 3pieces of cardboard soaked in white vinegar, and 3 washers to a form a battery.