Silver Oxide & Mercuric Oxide Batteries

Silver Oxide Batteries

Silver oxide (silver-zinc) batteries are round and come in two types: sodium hydroxide and potassium hydroxide. Sodium hydroxide batteries last about two to three years and are recommended for analog digital watches without backlights, while potassium hydroxides are a better option for LCD watches with backlights. Silver is expensive, but these batteries are available in small sizes where the amount of silver used is so small where price is not affected, or in larger sizes where the superior performance of the battery outweighs the cost.

In addition to watches, silver oxide batteries are also found in hearing aids, calculators and pagers. These batteries contain mercury, and are therefore hazardous and should not be sent to a landfill. The recycling/disposal process of these batteries involves shredding the batteries, neutralizing the electrolytes and recovering the heavy metals.

Mercuric Oxide Batteries

Mercury-containing batteries were phased out in the U.S. with the passing of the Mercury-Containing and Rechargeable Battery Management Act in 1996. It is because of this act that batteries are labeled with disposal information, such as, “Battery must be recycled.”

Several other countries have also banned the manufacturing of batteries that contain mercury, though they may still be used by some countries. Mercuric batteries were used in a number of electronic cameras and photography equipment, but have since been replaced with other batteries like zinc-air and silver-oxide. Check with your local recycling/disposal program about safely disposing of mercury containing batteries.