Mercury batteries were at one time one of the longest lasting and widely used batteries. However, the manufacture and sale of mercury batteries has been banned in most countries around the world due to the toxicity of mercury and environmental concerns. Mercury batteries were greatly used in their time and are still sought after by a select few. Here is a look at the uses and technology behind mercury batteries.

Mercury batteries belong to the primary cell group of batteries, meaning they are non-rechargeable. They use an electrolyte that provides a constant voltage rate which remains at a constant level for the life of the battery until the very end of the battery lifetime. At this point, the voltage current starts to drop at a steady sloping rate.

Along with the ability to provide a constant current, mercury batteries also have a very long shelf life of up to ten years. Because mercury batteries are able to hold a reliable and constant charge for extended periods, they are very useful for watches and hearing aids. For devices that require a current surge, such as flash photography or watch backlights, mercury batteries with a higher discharge rate are also useful.

Mercury batteries were ideal for photographers, and at the time, photography equipment depended on the functionality of that particular type. However, the improper disposal of mercury led to water source contamination, and thus the eventual ban of mercury batteries. Silver-oxide batteries are a current battery type that is the best replacement for mercury batteries, though the cost can be prohibitive for some. Silver oxide batteries have also replaced mercury batteries in hearing aids and watches.

There are also several other types of batteries that have replaced mercury technology over the years. For more information about silver oxide batteries and other technologies, please look for more informative articles about batteries.