1. What is the Battery Terminal Voltage Equation?

The Battery Terminal Voltage equation calculates the actual voltage available at the terminals of a battery when current is flowing. It accounts for the internal resistance of the battery which causes voltage drop under load.

2. How Does the Calculator Work?

The calculator uses the terminal voltage equation:

Where:

• \( V_{terminal} \) — Terminal voltage (V)
• \( EMF \) — Electromotive force (V)
• \( I \) — Current flowing (A)
• \( r \) — Internal resistance (Ω)

Explanation: The equation shows that the actual voltage available at the battery terminals decreases as current increases due to the voltage drop across the internal resistance.

3. Importance of Terminal Voltage Calculation

Details: Calculating terminal voltage is crucial for designing electrical circuits, determining battery performance under load, and ensuring proper operation of connected devices.

4. Using the Calculator

Tips: Enter EMF in volts, current in amperes, and internal resistance in ohms. All values must be non-negative.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between EMF and terminal voltage?
A: EMF is the maximum potential difference when no current flows, while terminal voltage is the actual voltage under load.

Q2: Why does terminal voltage decrease with increasing current?
A: The voltage drop across the internal resistance (I × r) increases with current, reducing the available terminal voltage.

Q3: What is typical internal resistance for batteries?
A: Internal resistance varies by battery type and size, typically ranging from milliohms to a few ohms.

Q4: Can terminal voltage be higher than EMF?
A: No, terminal voltage is always less than or equal to EMF when discharging. During charging, terminal voltage may exceed EMF.

Q5: How does temperature affect terminal voltage?
A: Lower temperatures generally increase internal resistance, causing greater voltage drop under load.