Ensure that the washers are clean and free from any oils or contaminants.

Cut the cardboard into circular shapes that match the size of your coins and washers.

• Dip the cardboard pieces into the saltwater solution, ensuring they are well soaked.

• Start with a coin as the bottom electrode, followed by a cardboard separator soaked in saltwater.
• Place a washer on top of the separator.
• Continue stacking coins, separators, and washers in this order until you have as many layers as you desire. The more layers you add, the higher the voltage output.

• Attach a wire or alligator clip to the top coin (copper side) and another to the bottom washer (zinc side).
• These wires will serve as the positive and negative terminals of your battery.

• Connect the wires to a small LED or a device that can be powered by low voltage. The LED should light up if your battery is generating enough voltage.

• You can experiment with the number of layers and different coin types to see how it affects the voltage and current output of your battery.
• Remember to disconnect the battery when not in use to avoid continuous chemical reactions.

This DIY battery demonstrates the principles of a voltaic cell, where the chemical reactions between the metals and the electrolyte generate a flow of electrons, creating electrical energy. Keep in mind that this homemade battery is relatively low in voltage and current .