Smoke alarm is actually another name for smoke sensor or smoke detector. Smoke alarm realizes fire prevention by monitoring the concentration of smoke. It uses an ion smoke sensor inside. Ion smoke sensor is a kind of sensor with advanced technology, stable and reliable operation. It is widely used in various fire alarm systems. Its performance is far better than gas-sensitive resistance fire alarm. It is mainly powered by cylindrical type lithium manganese dioxide battery CR123A and other models of batteries. This series of batteries has the characteristics of low discharge rate, high pulse discharge capacity, high capacity and long life.