1. What is Battery Capacity?

Battery capacity is a measure of the total energy a battery can store, typically measured in ampere-hours (Ah). For 12V systems, this calculator helps determine the appropriate battery size based on your energy requirements.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• Energy Required — Total watt-hours needed for your application
• 12V — Standard voltage for most deep-cycle batteries

Explanation: The formula converts watt-hours (energy) to ampere-hours (capacity) by dividing by the system voltage.

3. Importance of Battery Sizing

Details: Proper battery sizing ensures your system has enough power for its intended use while maximizing battery life and efficiency. Undersized batteries may discharge too quickly, while oversized batteries add unnecessary cost and weight.

4. Using the Calculator

Tips: Enter your total energy requirement in watt-hours. For systems that need to run for multiple days, multiply your daily requirement by the number of days of autonomy needed.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between Wh and Ah?
A: Watt-hours measure energy (power × time), while ampere-hours measure charge. For a given voltage, they can be converted using the formula above.

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

Q3: Does temperature affect battery capacity?
A: Yes, cold temperatures can significantly reduce available capacity. In cold climates, you may need to increase capacity by 50% or more.

Q4: How does depth of discharge affect battery life?
A: Most lead-acid batteries last longer when discharged to only 50% capacity rather than 80-100%. Lithium batteries typically allow deeper discharges.

Q5: Can I use this for 24V systems?
A: No, this calculator is specifically for 12V systems. For 24V systems, divide your watt-hour requirement by 24 instead of 12.