Battery Calculator Solar Generator

Battery Capacity Formula:

\[ \text{Battery Capacity (Ah)} = \frac{\text{Generator Solar Output (W)} \times \text{Generation Hours (h)} \times \text{Autonomy Days}}{\text{Battery Voltage (V)} \times \text{Depth of Discharge}} \]

Generator Solar Output:

watts

Generation Hours:

hours

Autonomy Days:

days

Battery Voltage:

volts

Depth of Discharge:

decimal (0-1)

Battery Capacity:

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1. What is the Battery Capacity Calculation?

The battery capacity calculation determines the required battery size (in amp-hours) for a solar generator system based on energy production, storage needs, and battery specifications. It helps ensure your system can meet power demands during periods without sunlight.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

Generator Solar Output — Power output of your solar generator in watts
Generation Hours — Daily hours of solar generation
Autonomy Days — Number of days the system should run without sun
Battery Voltage — Voltage of your battery bank
Depth of Discharge — Maximum recommended discharge level (typically 0.5-0.8)

Explanation: The formula calculates the total energy needed (watt-hours) divided by battery voltage and depth of discharge to determine required amp-hour capacity.

3. Importance of Battery Capacity Calculation

Details: Proper battery sizing ensures your solar system can meet energy demands during cloudy periods or at night, prevents battery damage from over-discharge, and optimizes system cost and performance.

4. Using the Calculator

Tips: Enter solar output in watts, generation hours per day, desired autonomy days, battery bank voltage, and recommended depth of discharge (typically 0.5 for lead-acid, 0.8 for lithium). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical depth of discharge value?
A: For lead-acid batteries use 0.5 (50%), for lithium batteries use 0.8 (80%). These values maximize battery life.

Q2: How do I determine generation hours?
A: Use peak sun hours for your location (typically 3-6 hours/day). Check solar insolation maps for accurate local data.

Q3: What are common battery voltages?
A: Common systems use 12V, 24V, or 48V. Higher voltages reduce current and wire size requirements.

Q4: How many autonomy days should I plan for?
A: Typically 1-3 days. More days increase cost but provide better reliability in cloudy weather.

Q5: Should I add a safety factor?
A: Yes, consider multiplying the result by 1.2-1.5 to account for inefficiencies and future expansion.