1. What is the Battery Size Calculation?

The battery size calculation determines the required battery capacity (in ampere-hours) needed to power an intruder alarm system through a UPS for a specified backup time. It ensures your alarm system remains operational during power outages.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( \text{Alarm VA} \) — Alarm system power consumption in volt-amps
• \( \text{Backup (h)} \) — Required backup time in hours
• \( \text{UPS DC Voltage (V)} \) — UPS battery bank voltage (typically 12V or 24V)

Explanation: The equation calculates the battery capacity needed by considering the power draw, required runtime, and system voltage.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures your intruder alarm system remains operational during power outages, maintaining security system functionality when it's needed most.

4. Using the Calculator

Tips: Enter the alarm system VA rating (found in specifications), desired backup time in hours, and UPS battery bank voltage (typically 12V). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Where do I find my alarm system's VA rating?
A: Check the alarm system specifications or nameplate - it's often listed as "Power Consumption" or "VA Rating".

Q2: What's a typical backup time for alarm systems?
A: Most security systems require 4-8 hours of backup, but local regulations may specify minimum requirements.

Q3: Why is UPS voltage important?
A: Different UPS systems use different battery bank voltages (12V, 24V, 48V). Using the wrong voltage will result in incorrect battery sizing.

Q4: Should I add a safety margin?
A: Yes, it's recommended to add 20-30% to the calculated Ah to account for battery aging and efficiency losses.

Q5: Can I use this for other security devices?
A: Yes, you can use it for any DC-powered security device if you know its power consumption in VA.