1. What is UPS Battery Runtime?

The UPS battery runtime is the estimated time a UPS system can power connected equipment during a power outage, based on battery capacity, voltage, efficiency, and the power draw of the connected load.

2. How Does the Calculator Work?

The calculator uses the UPS runtime equation:

Where:

• Battery Capacity — Total amp-hour rating of batteries
• Battery Voltage — Voltage of each battery
• Number of Batteries — Batteries in the UPS system
• Efficiency — UPS conversion efficiency (typically 0.8-0.95)
• Load Power — Total wattage of connected equipment

Explanation: The equation calculates total available energy (in watt-hours) and divides by the load power to determine runtime.

3. Importance of Runtime Calculation

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

4. Using the Calculator

Tips: Enter battery specifications from manufacturer datasheet, measure actual load power if possible, and use typical efficiency values (0.9 for most UPS systems).

5. Frequently Asked Questions (FAQ)

Q1: What's typical efficiency for a UPS?
A: Most modern UPS systems have 85-95% efficiency. Online UPS typically has higher efficiency than line-interactive models.

Q2: How does battery age affect runtime?
A: As batteries age, their capacity decreases. For older batteries (3+ years), multiply calculated runtime by 0.7-0.8 for more realistic estimates.

Q3: Should I use peak or average load power?
A: For critical applications, use peak load. For general estimates, average load provides typical runtime.

Q4: How accurate is this calculation?
A: It provides a theoretical maximum. Actual runtime may be 10-20% less due to temperature, battery condition, and power factor.

Q5: Can I connect different battery types?
A: Never mix battery types, ages, or capacities in a UPS system as this can reduce performance and lifespan.