1. What is Solar Battery Capacity?

Solar battery capacity refers to the amount of energy a battery can store, measured in kilowatt-hours (kWh). Proper sizing is crucial for ensuring your solar system can meet energy needs during periods without sunlight.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• Daily Energy Consumption — Your average daily energy usage in watt-hours
• Days of Autonomy — Number of days you want the battery to last without solar input
• Depth of Discharge — Percentage of battery capacity you can safely use (typically 0.5-0.8)
• Efficiency — System efficiency factor accounting for losses (typically 0.85-0.95)

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures reliable power supply, maximizes battery life, and optimizes system cost. Oversizing increases costs while undersizing leads to power shortages.

4. Using the Calculator

Tips:

• Measure your daily energy consumption from utility bills or energy monitor
• 3-5 days autonomy is typical for most home systems
• Lithium batteries typically allow 80-90% DoD, lead-acid 50%
• System efficiency is typically 85-95% for lithium, 70-85% for lead-acid

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my daily energy consumption?
A: Check your electricity bills for monthly kWh usage and divide by 30, or use an energy monitor for more precise measurement.

Q2: What's a typical depth of discharge for batteries?
A: Lithium-ion: 80-90%, Lead-acid: 50%, depending on battery type and manufacturer recommendations.

Q3: How many days of autonomy should I plan for?
A: Depends on location and solar resource. 3-5 days is common for residential systems.

Q4: What affects system efficiency?
A: Inverter efficiency, battery charge/discharge efficiency, temperature, and wiring losses all contribute.

Q5: Should I round up the calculated battery size?
A: Yes, it's recommended to round up to the nearest available battery size for safety margin.