How long must a battery in a fire alarm system be able to sound the notification appliances?

In fire alarm systems, the battery backup is essential to ensure that the system remains operational during a power outage, allowing for effective notification of occupants in case of an emergency. The correct duration for which a battery must be able to sound the notification appliances is five minutes. This time frame is established to allow sufficient time for all occupants to respond to the alarm and evacuate the premises safely. It is crucial for the battery to provide reliable power not only for the initial alarm activation but also to sustain the alert in case the situation necessitates longer evacuation times.

While shorter durations such as two or three minutes might suffice in certain situations, they do not meet the safety standards and requirements set forth for fire alarm systems, which emphasize preparedness and the need for adequate warning time for building occupants. A duration exceeding five minutes, such as seven minutes, may also be unnecessarily long and could lead to equipment inefficiencies and false alarms. Therefore, the five-minute requirement strikes a balance between safety and operational efficiency in fire alarm systems.