How long must a battery backup run in normal mode?

How long must a battery backup run in normal mode?

• A. 24 Hours
• B. 12 Hours
• C. 6 Hours
• D. 48 Hours

Answer: (A)

Battery backup is sized to keep the system operating for a full day without primary power. In normal mode, the system runs on main power, but the backup battery must be able to take over and sustain operation for 24 hours if that power is lost. This ensures continuous monitoring, signaling, and control during a typical outage, covering the critical first day until power is restored or a higher-level backup kicks in. Shorter durations (12 or 6 hours) risk loss of functionality if the outage lasts longer, while a 48-hour requirement would demand a much larger, more costly battery system that isn’t standard for most life-safety applications.

Battery backup is sized to keep the system operating for a full day without primary power. In normal mode, the system runs on main power, but the backup battery must be able to take over and sustain operation for 24 hours if that power is lost. This ensures continuous monitoring, signaling, and control during a typical outage, covering the critical first day until power is restored or a higher-level backup kicks in. Shorter durations (12 or 6 hours) risk loss of functionality if the outage lasts longer, while a 48-hour requirement would demand a much larger, more costly battery system that isn’t standard for most life-safety applications.