1. What is UPS Battery Run Time?

The UPS battery run time is the duration a UPS (Uninterruptible Power Supply) can power connected equipment during a power outage. It depends on battery capacity, voltage, system efficiency, and the power demand of connected devices.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• Battery Capacity — Total amp-hour rating of the battery
• Battery Voltage — Nominal voltage of the battery bank
• Efficiency — UPS conversion efficiency (typically 0.85-0.95)
• UPS Load — Total power consumption of connected devices

Explanation: The equation calculates how long the battery can sustain the load by converting battery energy (Ah × V) to watt-hours and dividing by the load in watts.

3. Importance of Run Time Calculation

Details: Accurate run time estimation helps ensure critical equipment remains powered during outages and helps determine appropriate UPS sizing for specific applications.

4. Using the Calculator

Tips: Enter battery capacity in amp-hours, voltage in volts, efficiency as a decimal (0-1), and load in watts. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's typical efficiency for a UPS?
A: Most UPS systems have 85-95% efficiency (0.85-0.95). Online UPS tend to be more efficient than line-interactive models.

Q2: How do I find my UPS load?
A: Check the UPS display, monitoring software, or measure with a wattmeter. Alternatively, sum the wattage of all connected devices.

Q3: Does battery age affect run time?
A: Yes, older batteries have reduced capacity. For critical applications, derate capacity by 20% for aging.

Q4: Can I extend run time?
A: Yes, by adding parallel battery banks, reducing load, or using more efficient equipment.

Q5: Why is my actual run time shorter than calculated?
A: Possible reasons include battery aging, higher actual load, lower efficiency at partial loads, or temperature effects.