1. What is Battery Watt-Hour?

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

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( Wh \) — Watt-hours (energy capacity)
• \( Ah \) — Amp-hours (charge capacity)
• \( V \) — Voltage (electrical potential)

Explanation: This calculation converts the battery's charge capacity (Ah) to energy capacity (Wh) by accounting for the voltage at which the energy is delivered.

3. Importance of Watt-Hour Calculation

Details: Knowing a battery's watt-hour rating helps compare different batteries, estimate runtime, and determine energy storage capacity. It's particularly important for sizing solar systems, electric vehicles, and portable electronics.

4. Using the Calculator

Tips: Enter the battery's amp-hour (Ah) rating and nominal voltage (V). Both values must be positive numbers. The calculator will compute the energy capacity in watt-hours (Wh).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between Ah and Wh?
A: Amp-hours measure charge capacity, while watt-hours measure energy capacity. Wh accounts for voltage, making it a more complete measure of battery capacity.

Q2: Why is watt-hour important for air travel?
A: Airlines restrict batteries by watt-hour rating (typically ≤100Wh for carry-on) because it better represents potential energy than amp-hours alone.

Q3: How do I convert Wh back to Ah?
A: Use the formula \( Ah = Wh / V \). You need to know the system voltage.

Q4: Are watt-hours additive in battery banks?
A: Yes, when connecting batteries in parallel (same voltage), watt-hours add directly. In series (voltage increases), watt-hours also add but voltage changes.

Q5: What's a typical watt-hour for common batteries?
A: A smartphone might have 10-15Wh, laptop 30-100Wh, car battery 500-1000Wh, and EV battery 50,000-100,000Wh.