To calculate battery capacity for a solar system, divide your total daily watt-hours by depth of discharge and system voltage to get amp-hours needed. Use the formula: Total Wh ÷ DoD ÷ Voltage =. . When it comes to solar energy and battery storage, two terms often create confusion: Amp Hours (Ah) and Watt Hours (Wh). Both are related to battery capacity, but they measure different things. Understanding the difference between them is essential for anyone working with solar power systems. . Terms like Amp-Hours (Ah) and Watt-Hours (Wh) often appear in battery specs, but what do they mean for your system's performance? This guide breaks down these metrics, explains their importance, and helps you choose the perfect battery for your solar setup. Amp-Hours (Ah) measure a battery's charge. . At the heart of these calculations are two fundamental units: amp hours (Ah) and watt hours (Wh). Let's break down the differences between them and why they matter for your energy storage system. Watt. . Amp-hours, or Ah, is a measure of how long a solar battery can power your home's appliances before it's completely drained. Use the. .