1. What is Battery Capacity Calculation?

The battery capacity calculation determines the required ampere-hour (Ah) rating of batteries needed to power a solar system for a specified autonomy period at a given system voltage.

2. How Does the Calculator Work?

The calculator uses the battery capacity formula:

Where:

• \( System\ Size\ kW \) — Total power requirement in kilowatts
• \( Autonomy\ h \) — Desired backup time in hours
• \( V \) — System voltage in volts

Explanation: The formula converts kW to watts (×1000), multiplies by desired runtime, then divides by system voltage to get ampere-hours.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures your solar system can meet power demands during periods without sunlight, prevents over-discharge of batteries, and optimizes system cost and performance.

4. Using the Calculator

Tips: Enter system size in kW, desired autonomy in hours, and system voltage in volts. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is autonomy time?
A: Autonomy time is the number of hours the system should run on battery power alone without solar input.

Q2: Should I add a safety margin?
A: Yes, it's recommended to add 20-30% to the calculated value to account for battery aging and inefficiencies.

Q3: What's the typical voltage for solar systems?
A: Common voltages are 12V, 24V, or 48V for residential systems, with higher voltages for larger installations.

Q4: How does temperature affect battery capacity?
A: Battery capacity decreases in cold temperatures - you may need to increase capacity by 10-20% in cold climates.

Q5: What's the difference between Ah and kWh?
A: Ah (ampere-hours) measures charge capacity, while kWh (kilowatt-hours) measures energy capacity. To convert: kWh = (Ah × V) / 1000.