mAh to Wh Calculator

Understanding the conversion between milliampere-hours (mAh) and watt-hours (Wh) is crucial for evaluating battery capacity accurately. This conversion helps in comparing batteries with different voltages and capacities effectively.

This article explores the technical details of mAh to Wh conversion, providing formulas, tables, and real-world examples. It also introduces an AI-powered calculator to simplify these calculations.

Artificial Intelligence (AI) Calculator for “mAh to Wh Calculator”

• Convert 3000 mAh at 3.7 V to Wh
• Calculate Wh for 5000 mAh battery with 7.4 V
• Find Wh from 1500 mAh and 12 V
• Determine Wh for 2500 mAh at 5 V

Comprehensive Tables of Common mAh to Wh Values

Below are detailed tables showing typical battery capacities in mAh, their nominal voltages, and the corresponding watt-hour values. These tables cover a wide range of practical battery types used in consumer electronics, electric vehicles, and industrial applications.

Fundamental Formulas for mAh to Wh Conversion

Converting milliampere-hours (mAh) to watt-hours (Wh) requires understanding the relationship between electric charge, voltage, and energy. The core formula is:

• Wh = Watt-hours, the energy capacity of the battery.
• mAh = Milliampere-hours, the charge capacity of the battery.
• V = Nominal voltage of the battery in volts.

The division by 1000 converts milliampere-hours to ampere-hours (Ah), since 1 Ah = 1000 mAh.

For clarity, the formula can also be expressed as:

Where:

• Ah = Ampere-hours (mAh / 1000)
• V = Voltage in volts

Additional considerations:

• Nominal Voltage (V): This is the average voltage during discharge, typically 3.7 V for lithium-ion cells.
• Capacity (mAh): Indicates how much charge the battery can store.
• Energy (Wh): Represents the total energy stored, useful for comparing batteries with different voltages.

Extended Formulas and Related Calculations

For more advanced applications, consider the following formulas:

• Energy in Joules (J): 1 Wh = 3600 J, so
  Energy (J) = Wh × 3600
• Battery Runtime Estimation: Given device power consumption (W), runtime (hours) can be estimated as:
  Runtime (h) = Wh / Power (W)
• Current (A) from mAh: To find current over time:
  Current (A) = mAh / 1000 / Time (h)

Real-World Application Examples of mAh to Wh Conversion

Example 1: Calculating Wh for a Smartphone Battery

A smartphone battery has a capacity of 3500 mAh and a nominal voltage of 3.7 V. Calculate the energy in watt-hours.

• Step 1: Convert mAh to Ah: 3500 mAh ÷ 1000 = 3.5 Ah
• Step 2: Apply the formula: Wh = Ah × V = 3.5 × 3.7 = 12.95 Wh

This means the smartphone battery stores approximately 12.95 watt-hours of energy.

Example 2: Estimating Battery Runtime for a Portable Speaker

A portable speaker uses a 5000 mAh battery rated at 7.4 V. The speaker consumes 10 watts during operation. Estimate the runtime.

• Step 1: Convert mAh to Ah: 5000 mAh ÷ 1000 = 5 Ah
• Step 2: Calculate Wh: Wh = 5 × 7.4 = 37 Wh
• Step 3: Calculate runtime: Runtime = Wh / Power = 37 / 10 = 3.7 hours

The speaker can operate approximately 3.7 hours on a full charge.

Additional Technical Insights on mAh to Wh Conversion

Battery manufacturers often specify capacity in mAh because it is a direct measure of charge. However, watt-hours provide a more comprehensive understanding of energy content, especially when comparing batteries with different voltages.

For example, two batteries with the same mAh rating but different voltages will have different energy capacities. This is why Wh is preferred in applications like electric vehicles and energy storage systems.

Voltage Variations and Their Impact

• Nominal Voltage: The average voltage during discharge, typically 3.6-3.7 V for lithium-ion cells.
• Fully Charged Voltage: Usually around 4.2 V for lithium-ion cells.
• Discharged Voltage: Can drop to about 3.0 V before the battery is considered empty.

When calculating Wh, nominal voltage is used for consistency, but actual energy delivered can vary depending on the discharge curve.

Battery Chemistry and Its Effect on mAh to Wh Conversion

Different battery chemistries have different nominal voltages:

When converting mAh to Wh, always use the nominal voltage specific to the battery chemistry for accurate results.

Practical Tips for Using mAh to Wh Calculators

• Always verify the nominal voltage of your battery before conversion.
• Use the calculator to compare batteries with different voltages effectively.
• Consider battery aging and efficiency losses; actual usable Wh may be lower.
• For multi-cell batteries, multiply the voltage by the number of cells in series.
• Use Wh for energy storage and runtime estimations rather than mAh alone.

Authoritative Resources and Standards

For further technical details and standards, consult the following authoritative sources:

• Battery Capacity and Energy – BatteryStuff.com
• IEEE Standards Association
• NREL Battery Energy Storage Handbook
• Batteries International Magazine

These resources provide in-depth technical knowledge and industry standards for battery capacity and energy calculations.