1. What is the Solar Battery Capacity Calculation?

The Solar Battery Capacity calculation determines the required battery bank size (in amp-hours) for a solar power system in New Zealand based on daily energy needs, desired autonomy days, and system voltage.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• NZ Daily Solar Yield — Your daily energy consumption or solar production (watt-hours)
• Autonomy Days — Number of days the system should run without sunlight
• Battery Voltage — System voltage (typically 12V, 24V, or 48V)

Explanation: The equation converts your total energy needs (daily yield × days) into battery capacity by accounting for the system voltage.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures your solar system can meet energy demands during periods of low sunlight while avoiding unnecessary costs from oversizing.

4. Using the Calculator

Tips: Enter your daily solar yield in watt-hours, desired autonomy days (typically 2-5 days in NZ), and system voltage (12V for small systems, 24V/48V for larger installations).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical daily solar yield in NZ?
A: Varies by location and system size, but average homes might use 5-15kWh daily (5000-15000Wh).

Q2: How many autonomy days should I plan for?
A: In NZ, 2-3 days is common, though more may be needed in winter or cloudy regions.

Q3: What battery voltage should I use?
A: 12V for small systems (<1kW), 24V for medium (1-3kW), 48V for larger systems (>3kW).

Q4: Should I add a safety margin?
A: Yes, consider adding 20-30% to account for battery aging and efficiency losses.

Q5: Does this account for battery depth of discharge?
A: No, divide the result by your battery's recommended DoD (e.g., 0.5 for 50% DoD).