1. What is Battery Size Calculation?

The battery size calculation determines the required battery capacity (in ampere-hours) needed to power an inverter load for a specified backup time at a given voltage. This is essential for designing reliable power backup systems.

2. How Does the Calculator Work?

The calculator uses the battery size formula:

Where:

• \( \text{Inverter Load} \) — Power consumption of connected devices in watts
• \( \text{Backup Time} \) — Desired runtime in hours
• \( \text{Voltage} \) — Battery system voltage (typically 12V, 24V, or 48V)

Explanation: The formula converts watt-hours to ampere-hours by dividing by the system voltage, giving the required battery capacity.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures sufficient backup time, prevents over-discharge (which damages batteries), and optimizes system cost and performance.

4. Using the Calculator

Tips: Enter the total wattage of all devices the inverter will power, desired backup time in hours, and system voltage. Common voltages are 12V (small systems), 24V (medium), or 48V (large).

5. Frequently Asked Questions (FAQ)

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

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

Q3: How does battery type affect the calculation?
A: Lead-acid batteries should only be discharged to 50% capacity for longevity, while lithium can often discharge to 80-90%.

Q4: What if my inverter has efficiency losses?
A: Divide the result by inverter efficiency (typically 0.85-0.95) for more accurate sizing.

Q5: Can I connect multiple batteries?
A: Yes, batteries can be connected in series (increases voltage) or parallel (increases capacity) to meet requirements.