1. What is Battery Bank Capacity?

The battery bank capacity calculation determines the required storage capacity (in amp-hours) for a solar power system based on your daily energy needs, desired days of autonomy, and system characteristics.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• Daily Energy Consumption — Your total daily energy usage in watt-hours
• Days of Autonomy — Number of days the system should run without sun
• Battery Voltage — System voltage (typically 12V, 24V, or 48V)
• Depth of Discharge — Fraction of battery capacity that can be safely used (0-1)
• Efficiency — System efficiency factor accounting for losses (0-1)

3. Importance of Proper Sizing

Details: Proper battery bank sizing ensures your solar system can meet your energy needs during periods of low sunlight while maximizing battery life and system efficiency.

4. Using the Calculator

Tips:

• Measure your actual daily energy consumption for accurate results
• Typical Depth of Discharge: 0.5 for lead-acid, 0.8-0.9 for lithium
• System efficiency is typically 0.8-0.9 (80-90%)
• More days of autonomy require larger battery banks

5. Frequently Asked Questions (FAQ)

Q1: What is a typical Depth of Discharge?
A: 50% for lead-acid batteries (to prolong life), 80-90% for lithium batteries.

Q2: How many days of autonomy should I plan for?
A: Typically 2-5 days depending on location and reliability needs.

Q3: What's the difference between Wh and Ah?
A: Watt-hours measure energy (power × time), amp-hours measure charge (current × time). Convert using: Wh = Ah × V.

Q4: How does temperature affect battery capacity?
A: Cold temperatures reduce available capacity - may need to oversize in cold climates.

Q5: Should I add a safety factor?
A: Yes, consider adding 10-20% to the calculated capacity for aging and unexpected loads.