1. What is the Electric Motor Power Formula?

The electric motor power formula calculates horsepower (HP) from voltage, current, and efficiency. This helps model boat enthusiasts determine the actual power output of their electric motors.

2. How Does the Calculator Work?

The calculator uses the electric motor power formula:

Where:

• \( Voltage \) — Electrical potential in volts (V)
• \( Current \) — Electrical current in amperes (A)
• \( Efficiency \) — Motor efficiency as decimal (0-1)
• 746 — Conversion factor from watts to horsepower

Explanation: The formula converts electrical power (volts × amps) to mechanical power (horsepower) accounting for motor efficiency.

3. Importance of Motor Power Calculation

Details: Accurate power calculation helps in selecting the right motor for your model boat, ensuring proper speed and performance without overloading the motor.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and efficiency as decimal between 0 and 1 (e.g., 85% = 0.85). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical efficiency value for model boat motors?
A: Most electric motors have efficiencies between 70-90% (0.7-0.9), with brushless motors typically more efficient than brushed ones.

Q2: How does this relate to thrust?
A: While HP indicates power, thrust depends on propeller design. More HP generally allows for larger props and/or higher RPM.

Q3: What voltage should I use?
A: Use your battery's nominal voltage (e.g., 12V for a 3S LiPo). For more accurate results, measure under load.

Q4: Why divide by 746?
A: 746 watts = 1 horsepower. This converts the electrical power calculation to mechanical horsepower.

Q5: Can I use this for other electric motors?
A: Yes, this formula works for any DC electric motor when you know the input voltage, current draw, and efficiency.