1. What is Solar Battery Sizing?

Solar battery sizing calculates the required battery capacity (in amp-hours) to power your electrical loads for a specified duration, considering the system voltage and recommended depth of discharge.

2. How Does the Calculator Work?

The calculator uses the battery sizing formula:

Where:

• \( \text{Load Power} \) — Total power consumption of your electrical loads in watts
• \( \text{Runtime} \) — Desired backup time in hours
• \( \text{Voltage} \) — System voltage (typically 12V, 24V, or 48V)
• \( \text{Depth of Discharge} \) — Fraction of battery capacity that can be safely used (typically 0.5-0.8)

Explanation: The formula converts watt-hours to amp-hours while accounting for how much of the battery's capacity can actually be used.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures your solar system can meet power demands without over-discharging batteries (which reduces lifespan) or overspending on unnecessary capacity.

4. Using the Calculator

Tips:

• Calculate total wattage of all loads that will run simultaneously
• Determine how many hours you need backup power
• Use your system voltage (12V, 24V, or 48V)
• Typical Depth of Discharge: 0.5 for lead-acid, 0.8 for lithium

5. Frequently Asked Questions (FAQ)

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

Q2: Should I add a safety margin?
A: Yes, add 20-25% to account for inefficiencies and battery aging.

Q3: How does temperature affect battery size?
A: Cold temperatures reduce capacity - you may need to increase size by 10-20% in cold climates.

Q4: What if my loads aren't constant?
A: Calculate for your highest continuous load scenario or use an energy audit.

Q5: How does this relate to solar panel sizing?
A: Battery sizing determines storage capacity, while panel sizing determines recharge capability - both are needed for complete system design.