1. What is the Watts to Amp-Hour Calculator?

This calculator converts power consumption in watts to battery capacity in amp-hours (Ah), which is essential for determining how long a battery will last under a specific load or sizing a battery bank for a particular application.

2. How Does the Calculator Work?

The calculator uses the battery capacity equation:

Where:

• \( Power \) — Power consumption in watts (W)
• \( Time \) — Duration in hours (h)
• \( Voltage \) — Battery voltage in volts (V)

Explanation: The equation converts energy (watt-hours) to battery capacity (amp-hours) by accounting for the system voltage.

3. Importance of Battery Capacity Calculation

Details: Accurate battery capacity calculation is crucial for designing power systems, sizing battery banks for solar installations, determining runtime for backup systems, and ensuring proper power supply for electronic devices.

4. Using the Calculator

Tips: Enter power in watts, time in hours, and system voltage in volts. All values must be positive numbers. The result shows the required battery capacity in amp-hours (Ah).

5. Frequently Asked Questions (FAQ)

Q1: Why convert watts to amp-hours?
A: Batteries are typically rated in amp-hours (Ah), while devices are rated in watts. This conversion helps match power requirements with battery capacity.

Q2: What's the difference between Ah and Wh?
A: Amp-hours (Ah) measure charge capacity, while watt-hours (Wh) measure energy capacity. Wh = Ah × V. This calculator converts between them.

Q3: How does voltage affect the calculation?
A: Higher voltage systems require fewer amp-hours for the same power. A 100W load on 12V needs 8.33A, but only 4.17A on 24V.

Q4: Should I derate the battery capacity?
A: Yes, for lead-acid batteries, typically multiply by 1.2-1.5 to account for depth-of-discharge limitations and efficiency losses.

Q5: Does temperature affect battery capacity?
A: Yes, cold temperatures can significantly reduce available capacity, especially for lead-acid batteries.