Button batteries are small, round batteries that are widely used in portable electronic devices, especially in POS (point of sale) machines. As the core equipment of modern retail, catering and other industries, POS machines require stable and reliable power support to ensure real-time processing and storage of transaction data. Button batteries provide power for the real-time clock (RTC) and memory backup of POS machines, ensuring that data is not lost even when the main power is disconnected.