Honeywell Fire Alarm Panel Battery Calculator

Understanding Honeywell Fire Alarm Battery Calculations

Proper battery sizing is a critical engineering requirement for any life safety installation. Honeywell fire alarm control panels require reliable secondary power supplies to maintain continuous operation during grid power outages. NFPA standards mandate that secondary power supplies must have adequate capacity to power the entire fire alarm system in standby mode followed by alarm notification operation. Utilizing 8.0 backend calculations allows system integrators to quickly process multiple electrical loading parameters and select appropriate sealed lead-acid battery configurations.

Formula Used

The total required Amp-Hours (Ah) is derived using the following comprehensive mathematical formula:

$$AH_{total} = \left( (I_{standby} + I_{aux}) \times T_{standby} + I_{alarm} \times T_{alarm} \right) \times DF \times SF \times TF$$

Where:

• $I_{standby}$: Panel quiescent current draw in amperes.
• $I_{aux}$: Auxiliary device load connected to the panel terminals.
• $T_{standby}$: Required standby duration hours (typically 24 hours).
• $I_{alarm}$: Total alarm current including notification appliance circuits.
• $T_{alarm}$: Alarm duration converted into hours (e.g., 0.5 hours for 30 minutes).
• $DF$: Battery aging derating factor to account for capacity reduction over time.
• $SF$: Design safety factor for unexpected additions.
• $TF$: Temperature correction factor for extreme installation environments.

How to Use This Calculator

1. Input the quiescent standby current specified in your Honeywell panel data sheet.
2. Enter the maximum alarm current consumed by horns, strobes, and modules.
3. Specify the mandatory standby hours and alarm duration minutes.
4. Adjust safety, temperature, and aging derating factors according to project specifications.
5. Click the calculate button to instantly view precise battery requirements.

Frequently Asked Questions