What must smoke alarms powered by AFCI have?

Smoke alarms powered by Arc Fault Circuit Interrupter (AFCI) require a source of secondary power to ensure their operation during a power outage or when the primary power source is interrupted. This secondary power typically comes in the form of battery backup, which allows the smoke alarm to function even if the electrical supply from the AFCI is cut off.

Having a secondary power source is crucial for maintaining the smoke alarm’s functionality, providing a layer of safety in emergency situations. A smoke alarm without a secondary power source would not be reliable in situations where its primary power might fail, making it essential to have that battery backup.

While primary power sources are necessary to operate smoke alarms during standard conditions, the inclusion of a secondary power source is specifically mandated to enhance safety and reliability, ensuring that the alarm will continue to function when needed most.