1. What is Battery Energy (Wh)?

Watt-hour (Wh) is a unit of energy that measures the capacity of a battery to do work. It represents how much energy a battery can deliver over time and is calculated by multiplying the battery's amp-hour (Ah) rating by its voltage (V).

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( \text{Capacity} \) — Battery capacity in amp-hours (Ah)
• \( \text{Voltage} \) — Battery nominal voltage in volts (V)

Explanation: This calculation gives the total energy storage capacity of the battery, which is useful for comparing batteries of different voltages and capacities.

3. Importance of Watt-Hour Calculation

Details: Knowing the watt-hour rating helps determine how long a battery will last powering a device, allows comparison between different battery types, and is essential for airline travel regulations regarding lithium batteries.

4. Using the Calculator

Tips: Enter the battery capacity in Ah (usually marked on the battery) and the nominal voltage (e.g., 3.7V for single-cell lithium-ion). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why calculate watt-hours for lithium batteries?
A: Watt-hours provide a standardized way to compare energy capacity across different battery chemistries and configurations.

Q2: What's typical Wh for common lithium batteries?
A: A 18650 cell might be about 10Wh (3.7V × 2.7Ah), while smartphone batteries range from 10-20Wh.

Q3: How does this relate to mAh ratings?
A: mAh only tells part of the story - you need voltage to get the complete energy picture (Wh = Ah × V).

Q4: Are there limitations to this calculation?
A: This gives theoretical maximum energy; actual usable energy depends on discharge rate, temperature, and battery age.

Q5: Why is this important for air travel?
A: Airlines restrict lithium batteries by watt-hour rating (typically ≤100Wh allowed in carry-on without approval).