1. What is the Battery Size Calculation?

The battery size calculation determines the required battery capacity (in ampere-hours) needed to support a UPS load for a specified backup time at a given voltage. This ensures your UPS system has adequate battery power for your needs.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( \text{UPS Load} \) — Power consumption of connected equipment in watts
• \( \text{Backup} \) — Desired backup time in hours
• \( V \) — Battery bank voltage

Explanation: The formula converts watt-hours to ampere-hours by dividing by the system voltage.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures your UPS can provide adequate backup time for critical loads while avoiding oversized batteries that increase cost and space requirements.

4. Using the Calculator

Tips: Enter the total UPS load in watts, desired backup time in hours, and system voltage. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Should I add a safety margin to the calculated size?
A: Yes, it's recommended to add 20-25% to account for battery aging and inefficiencies.

Q2: What's the difference between Ah and Wh?
A: Amp-hours (Ah) measure charge capacity, while watt-hours (Wh) measure energy capacity. They're related by voltage (Wh = Ah × V).

Q3: How does battery type affect the calculation?
A: Lead-acid batteries typically shouldn't be discharged below 50% capacity, so you may need to double the calculated size.

Q4: What if my UPS has multiple batteries?
A: For batteries in parallel, add their Ah ratings. In series, voltage adds while Ah stays the same.

Q5: How often should I recalculate my battery needs?
A: Re-evaluate whenever your load changes significantly or every 2-3 years as batteries age.