Solar Battery Bank Size Calculator India

Battery Bank Size Formula:

\[ Size = \frac{Load \times Autonomy}{V \times DoD \times Efficiency} \]

Load (Wh):

Autonomy (days):

days

Voltage (V):

Depth of Discharge (DoD):

decimal

Efficiency:

decimal

Battery Bank Size:

Unit Converter ▲

Unit Converter ▼

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1. What is Solar Battery Bank Sizing?

Solar battery bank sizing is the process of determining the appropriate capacity (in Ah) of batteries needed to store enough energy for your specific requirements, considering factors like daily energy consumption, days of autonomy, system voltage, depth of discharge, and efficiency.

2. How Does the Calculator Work?

The calculator uses the following formula:

\[ Size = \frac{Load \times Autonomy}{V \times DoD \times Efficiency} \]

Where:

\( Load \) — Daily energy consumption in Watt-hours (Wh)
\( Autonomy \) — Number of days the system should run without sun
\( V \) — System voltage (typically 12V, 24V, or 48V)
\( DoD \) — Depth of Discharge (decimal, e.g., 0.8 for 80%)
\( Efficiency \) — System efficiency (decimal, typically 0.8-0.95)

Explanation: The formula calculates the required battery capacity in Ampere-hours (Ah) to meet your energy needs while accounting for system losses and battery preservation.

3. Importance of Proper Battery Sizing

Details: Proper battery sizing is crucial for ensuring your solar power system meets your energy needs, extends battery life, prevents over-discharge, and provides reliable power during periods of low sunlight.

4. Using the Calculator

Tips: Enter your daily energy consumption in Wh, desired days of autonomy, system voltage, appropriate depth of discharge (typically 0.5-0.8 for lead-acid, 0.8-0.9 for lithium), and system efficiency (typically 0.8-0.9).

5. Frequently Asked Questions (FAQ)

Q1: What is a typical DoD value for different battery types?
A: Lead-acid batteries: 50-80%, Lithium-ion: 80-90%, AGM: 50-80%, Gel: 50-80%.

Q2: How do I calculate my daily energy consumption?
A: Sum the wattage of all appliances multiplied by their daily usage hours. For example: (100W light × 5 hours) + (50W fan × 8 hours) = 900 Wh.

Q3: What is a reasonable autonomy period for India?
A: Typically 1-3 days depending on location and season. Coastal areas may need less, while northern regions might need more during winter.

Q4: How does system voltage affect battery sizing?
A: Higher voltages (24V, 48V) require lower Ah capacities for the same energy storage, which can be more efficient for larger systems.

Q5: Should I add a safety margin to the calculated size?
A: Yes, it's recommended to add 10-20% safety margin to account for battery aging, temperature variations, and unexpected load increases.