1. What is Solar Battery Bank Sizing?

Solar battery bank sizing calculates the required battery capacity (in amp-hours) needed to store energy from your solar array, considering your system's voltage, daily usage hours, and efficiency factors.

2. How Does the Calculator Work?

The calculator uses the battery bank sizing equation:

Where:

• \( Solar\ Array\ W \) — Solar array wattage
• \( h \) — Daily usage hours
• \( Eff \) — System efficiency (typically 0.7-0.85)
• \( Bank\ V \) — Battery bank voltage (typically 12V, 24V, or 48V)

Explanation: The equation accounts for total daily energy needs (watt-hours), system losses (efficiency), and converts to battery capacity (amp-hours) at your system voltage.

3. Importance of Proper Sizing

Details: Proper battery bank sizing ensures your system can meet energy demands during periods without sun, prevents battery damage from over-discharge, and optimizes system cost and performance.

4. Using the Calculator

Tips: Enter solar array wattage, daily usage hours, system efficiency (default 0.85), and battery bank voltage (default 12V). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical efficiency value?
A: Most systems use 0.7-0.85 (70-85%). Lower values account for more system losses.

Q2: How do I account for multiple days without sun?
A: Multiply the result by your desired days of autonomy (typically 2-5 days).

Q3: What about depth of discharge (DOD)?
A: Divide the result by your battery's recommended DOD (e.g., 0.5 for 50% DOD).

Q4: Does this work for lithium batteries?
A: Yes, but lithium batteries have different voltage characteristics and DOD considerations.

Q5: How do I convert to kWh?
A: Multiply Ah by bank voltage and divide by 1000 (kWh = Ah × V / 1000).