Silver Oxide Batteries
Many brands and types of packaging, mercury-free of course
These batteries, especially in button cell design are primarily used in watches and therefore also referred to as “watch batteries.”Due to the variety of available sizes, their capacity and reliability, these batteries are also used in other electronic devices, such in medical technology.
Silver oxide batteries have to be disposed of properly in Germany according to the Battery Act (BattG) (and in many other countries as well, because the BattG is based on a European directive). Batteries are collected at retail locations in containers provided for that purpose. Batteries should not be disposed of in any other waste collection containers or in the environment because they contain contaminants and recoverable materials.
Silver oxide zinc cells (short: “silver cells”) are primary cells. They are commercially mainly available as button cells and carry the IEC designation “SR.” In Europe, however, a three-digit number (such as 377) is more common.
The negative pole of a silver oxide zinc cell consists of zinc powder, which is oxidized in the course of discharge. The positive pole is made of silver oxide which is reduced to elemental silver upon discharging. When disposing of these batteries, the pure silver is recovered. Diluted potassium hydroxide (or sodium hydroxide) is used as the electrolyte. The nominal voltage of such a cell is about 1.55 V. It is particularly advantageous that the voltage remains almost constant during discharge.