1. What is the Firelite Battery Calculation?

The Firelite battery calculation determines the required battery capacity (in ampere-hours) for Firelite fire alarm control panels based on standby current and alarm current draw.

2. How Does the Calculator Work?

The calculator uses the Firelite battery equation:

Where:

• Firelite Standby A — Standby current in amps
• Alarm A — Alarm current in amps
• 24 — Hours of standby operation required
• 0.083 — 5 minutes converted to hours (0.0833)
• 1.25 — Safety factor (25% additional capacity)

Explanation: The equation calculates total energy needed for 24 hours of standby plus 5 minutes of alarm, then adds a 25% safety margin.

3. Importance of Proper Battery Sizing

Details: Proper battery sizing ensures the fire alarm system remains operational during power outages for code-required durations while maintaining sufficient capacity for alarm operation.

4. Using the Calculator

Tips: Enter standby current and alarm current in amps. Values must be positive numbers. Typical values range from 0.1A to several amps depending on system size.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a 1.25 multiplier?
A: The 1.25 multiplier (25% additional capacity) accounts for battery aging, temperature effects, and provides a safety margin.

Q2: What battery types are suitable?
A: Sealed lead-acid (SLA) batteries are typically used, sized to meet or exceed the calculated capacity.

Q3: How often should batteries be replaced?
A: NFPA recommends replacement every 3-5 years or when capacity drops below 80% of rated capacity.

Q4: Does this calculation meet code requirements?
A: This follows NFPA 72 requirements for 24 hours standby plus 5 minutes alarm, but always verify local codes.

Q5: What if my system has multiple alarm currents?
A: Use the highest alarm current draw expected during full system activation.