Batteries are made from multiple electrochemical cells that convert stored energy into usable electrical energy. For commonly available disposable batteries, the cells can be a combination of carbon, lithium, magnesium, silver oxide, alkaline zinc–manganese dioxide or nickel.
Batteries include a positive electrode, a negative electrode, a separator and an electrolyte. The electrodes vary by battery type, but the separators and electrolytes are often the same regardless of type or brand. The most common and inexpensive disposable battery is the zinc-carbon variant, while the most expensive disposable battery is silver oxide, often used in button cell batteries for watches and other small electronics. Lithium variants are frequently used in high-drain applications because they are longer-lived, albeit more expensive, than zinc-carbon batteries.