1. What is Battery Capacity Calculation?

The battery capacity calculation determines the required battery bank size (in amp-hours) for a solar-powered 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 — How many days you want the system to run without sun
• Battery Voltage — System voltage (typically 12V, 24V, or 48V)
• Depth of Discharge — Maximum safe discharge level (typically 0.5-0.8)
• Efficiency — System efficiency factor (typically 0.8-0.95)

Explanation: The formula accounts for your energy needs, backup requirements, and system losses to determine the minimum battery capacity needed.

3. Importance of Proper Sizing

Details: Correct battery sizing ensures your system can meet your energy needs while protecting battery life. Undersizing leads to power shortages, while oversizing increases costs unnecessarily.

4. Using the Calculator

Tips: For accuracy, measure your actual daily consumption with an energy monitor. Typical depth of discharge is 50% for lead-acid, 80% for lithium. System efficiency is typically 85-95%.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical depth of discharge?
A: 50% for lead-acid batteries, 80% for lithium batteries to maximize battery life.

Q2: How many days of autonomy should I choose?
A: 2-5 days is typical. More for unreliable sunlight areas, less for grid-tied systems.

Q3: What affects system efficiency?
A: Inverter efficiency, charge controller efficiency, wiring losses, and temperature effects.

Q4: Should I round up the battery size?
A: Yes, always round up to the nearest standard battery size and consider future expansion.

Q5: How do I convert kWh to watt-hours?
A: Multiply kWh by 1000 (e.g., 10 kWh/day = 10,000 Wh/day).