1. What is Battery Capacity Calculation?

The battery capacity calculation determines the required battery bank size (in amp-hours) needed to power your home for a specified number of days without solar input, accounting for system efficiency and safe discharge limits.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• Daily Energy Consumption — Your home's average daily energy usage in watt-hours
• Days of Autonomy — Number of days you want backup power for
• 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 0.85-0.95)

3. Importance of Proper Sizing

Details: Correct battery sizing ensures your solar system can meet your energy needs during periods of low sunlight while maximizing battery life by staying within recommended discharge limits.

4. Using the Calculator

Tips: For accurate results, use actual energy consumption data from your utility bills. Typical values: Depth of Discharge = 0.8 (80%) for lithium batteries, 0.5 (50%) for lead-acid. Efficiency is typically 0.95 for lithium systems.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical daily energy consumption?
A: Average US home uses about 30kWh/day (30,000Wh), but this varies widely by home size and efficiency.

Q2: How many days of autonomy should I plan for?
A: 3 days is common for most locations, but areas with frequent storms may need 5+ days.

Q3: What battery voltage should I use?
A: 48V is most common for whole-home systems as it reduces current and wiring costs.

Q4: Why account for depth of discharge?
A: Deeper discharges reduce battery lifespan. The calculator ensures you stay within safe limits.

Q5: Should I round up the calculated capacity?
A: Yes, always round up to the nearest standard battery size and consider adding 10-20% buffer.