1. What is the Battery Life Equation?

The battery life equation calculates how long a battery will last based on its capacity and the current draw of the device it powers. It provides a simple way to estimate battery runtime for electronic devices.

2. How Does the Calculator Work?

The calculator uses the battery life equation:

Where:

• \( Capacity \) — Battery capacity in milliamp-hours (mAh)
• \( Current \) — Device current draw in milliamps (mA)

Explanation: The equation divides the total charge capacity of the battery by the rate at which charge is being used to determine how many hours the battery will last.

3. Importance of Battery Life Calculation

Details: Accurate battery life estimation is crucial for designing portable electronics, selecting appropriate batteries for devices, and planning power requirements.

4. Using the Calculator

Tips: Enter battery capacity in mAh and current draw in mA. Both values must be positive numbers. Typical battery capacities range from 100mAh (small button cells) to 10,000mAh (large power banks).

5. Frequently Asked Questions (FAQ)

Q1: Why use mAh for capacity and mA for current?
A: Using matching units (milliamps) makes the calculation straightforward and eliminates the need for unit conversions.

Q2: What are typical battery capacities?
A: Common capacities: AA alkaline ~2000-3000mAh, smartphone ~3000mAh, laptop ~4000-8000mAh, car battery ~50,000mAh.

Q3: Does this account for battery efficiency?
A: No, this is a theoretical maximum. Real-world battery life may be 10-30% less due to temperature, age, and discharge rate effects.

Q4: Can I use this for different battery types?
A: Yes, the equation works for any battery type (Li-ion, NiMH, alkaline) but discharge characteristics vary between chemistries.

Q5: How accurate is this calculation?
A: It provides a good estimate for constant current loads. For variable loads, use average current or more complex calculations.