When looking to power up your camera, a wireless thermometer or even a keyboard, you can rely on good old Alkaline batteries. Chemically, a typical Alkaline dry cell battery is a non-rechargeable cell with Zinc and manganese dioxide as electrodes. Primary batteries are available in various sizes according to the applications. For instance, AA is the most widely used Alkaline battery size, while AAA, C, D, or 9V are used for specific devices which have steady demand. All of these products are likely to be used immediately after purchase, which make them suitable for use even during emergency scenarios. Compared with Zinc-carbon or Zinc chloride batteries, Alkaline shells have a higher energy density, longer shelf life, and don’t contain toxic heavy metals like Lead or Cadmium.