Battery Calculations

Command

Command Description
ATEXPORT_BATTERY_CALCULATIONS Export battery calculation reports to Excel

Prerequisites

  • A FireCAD project must be open

Overview

Exports battery calculation reports per NFPA 72 requirements, showing standby current, alarm current, required battery capacity, and derating calculations for each panel.

Steps

  1. Type ATEXPORT_BATTERY_CALCULATIONS in the AutoCAD command line
  2. Select the panels to include
  3. The report is generated as an Excel file

Calculation Formula

Required Ah = (Standby Current x Standby Hours + Alarm Current x Alarm Minutes/60) x Derating Factor

Default values (configurable in Options):

  • Standby: 24 hours
  • Alarm: 5 minutes
  • Derating Factor: 1.2

Report Options

The Select Circuits dialog includes a Battery Calculation Settings tab with options specific to this report:

  • Show Speaker Currents (W ÷ V = A) — Converts speaker wattage to alarm current using the circuit voltage, so speakers appear in battery calculations alongside current-based devices
  • Show Only Circuit Current Totals (Hide Part Details) — Collapses individual devices to circuit-level totals
  • Include Cell Formulas — Embeds Excel formulas for standby/alarm current totals
  • Include Circuits Without Current — Shows circuits that have zero standby and alarm current
  • Ignore Spare Circuits — Excludes spare/unused circuits from the report

Tips

  • Battery calculation parameters are configured in Options & Configuration under the Reports tab
  • NFPA 72 Section 10.6.7.2 defines the 24-hour standby + alarm time requirements

Related Commands


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