How do you build a 12 volt car battery from scratch?

Building a 12-volt car battery from scratch involves assembling six individual cells, each producing about 2.1 volts. You can create these cells using lead-acid materials, which include lead dioxide for the positive plates, sponge lead for the negative plates, and an electrolyte solution of sulfuric acid and water. Properly connect the cells in series to achieve the desired voltage, ensuring all components are well-insulated and safely housed in a durable case. Be sure to follow safety protocols, as working with lead and sulfuric acid can be hazardous.