1. What is the Battery Size Calculation?

The battery size calculation determines the required battery capacity (in ampere-hours) to power an inverter AC unit for a specified duration at a given voltage. This is essential for proper system design and ensuring adequate backup power.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( \text{Inverter AC W} \) — Power consumption of the AC in watts
• \( \text{Time} \) — Duration of operation in hours
• \( \text{V} \) — System voltage in volts

Explanation: The equation calculates the total energy requirement (watt-hours) and converts it to battery capacity (ampere-hours) based on the system voltage.

3. Importance of Battery Size Calculation

Details: Proper battery sizing ensures your inverter AC system will operate for the desired duration without over-discharging the batteries, which can extend battery life and improve system reliability.

4. Using the Calculator

Tips: Enter the AC's wattage (found on the nameplate or specifications), the desired runtime in hours, and the system voltage (typically 12V, 24V, or 48V for most inverter systems).

5. Frequently Asked Questions (FAQ)

Q1: Should I add a safety margin to the calculated battery size?
A: Yes, it's recommended to add 20-30% to account for inefficiencies, battery aging, and unexpected loads.

Q2: What if my AC has a SEER rating instead of watts?
A: You'll need to convert BTU/h to watts (1 BTU/h ≈ 0.293W) using the SEER rating to estimate power consumption.

Q3: Does this account for inverter efficiency?
A: No, this is a basic calculation. For more accuracy, divide the result by your inverter's efficiency (typically 0.85-0.95).

Q4: How does temperature affect battery capacity?
A: Cold temperatures reduce battery capacity. In cold climates, you may need to increase battery size by 20-50%.

Q5: What about depth of discharge (DOD)?
A: To extend battery life, don't discharge below 50% for lead-acid batteries. Double the calculated size for 50% DOD.