When shopping for batteries, you may feel overwhelmed by choices. Not only are many name brands available, but each brand also offers several different types from which to choose. You may wonder what distinguishes a common alkaline battery from its heavy-duty "dry cell" cousin, especially since the prices are similar. In short, alkaline batteries tend to last longer, hold up in more environments and retain their capacity for a longer period of time.
While alkaline batteries are actually a type of dry-cell batteries, their chemical composition is unique. Within a dry-cell battery's metal cylinder is a graphite rod surrounded by a combination of ammonium chloride and manganese dioxide. When these chemicals react with one another, the oxidation allows a small amount of electrical current to pass through the rod. An alkaline battery contains potassium hydroxide in the place of the ammonium chloride.
The use of an alkaline compound in the construction of the battery gives it the capacity for far more energy than a standard dry-cell battery. Whereas the latter can typically produce around 50 percent more power than an old-fashioned carbon zinc battery under the same electrical load, an alkaline battery can produce anywhere from 500 to 700 percent more power than the identical carbon zinc variety.
A glaring disadvantage of dry-cell batteries compared to alkaline ones is their inability to be stockpiled and stored for long periods of time. A standard dry-cell battery can only be stored for about two years before its performance capacity has been completely spent. In contrast, alkaline batteries only lose about 5 percent of their storage capacity each year, meaning they can effectively be stored for 10 times as long as a dry-cell variety.
Performance in Different Environments
Another advantage of the alkaline battery over a standard dry-cell one is its ability to be used in different temperatures. A dry-cell battery can perform well in temperatures ranging from around 0 to 160 degrees Fahrenheit. However, an alkaline battery is rated for performance in climates as low as -20 degrees. This makes the alkaline variety far more useful in environments and situations where extreme cold can be a factor.