1. What is the Battery Capacity Calculation?

The battery capacity calculation determines the minimum required battery size (in ampere-hours) for a Fire Lite fire alarm control panel to maintain 24 hours of standby power plus 5 minutes of alarm power, with a 25% safety factor.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• Standby Current — Normal operating current of the system (amps)
• Alarm Current — Current draw during alarm condition (amps)
• 24 hours — Required standby duration
• 0.083 hours — 5 minutes of required alarm duration
• 1.25 — 25% safety factor

Explanation: The equation calculates total energy requirements then adds a 25% buffer to account for battery aging and temperature effects.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing is critical for fire alarm system reliability. Undersized batteries may fail during emergencies, while oversized batteries increase cost unnecessarily.

4. Using the Calculator

Tips: Enter standby current and alarm current in amps. Values should be from manufacturer specifications or actual measurements. All values must be non-negative.

5. Frequently Asked Questions (FAQ)

Q1: Where do I find standby and alarm current values?
A: These values are typically listed in the Fire Lite control panel technical specifications or can be measured with an ammeter.

Q2: Why is there a 25% safety factor?
A: The safety factor accounts for battery aging, temperature effects, and manufacturing variations.

Q3: What if my system has multiple alarm currents?
A: Use the highest alarm current that would be drawn during any single alarm condition.

Q4: Does this calculation work for all battery types?
A: This calculation is designed for lead-acid batteries commonly used in fire alarm systems. Other battery types may require different calculations.

Q5: How often should batteries be replaced?
A: NFPA recommends battery replacement every 3-5 years, or when capacity drops below 80% of rated capacity.