Kilowatt Hour (kWh) to Milliampere Hour (mAh) Calculator

Convert energy in Kilowatt Hours (kWh) to battery capacity in Milliampere Hours (mAh). Enter the energy and voltage specifications to calculate the equivalent battery capacity.

Energy Specifications

How to Use this Kilowatt Hour (kWh) to Milliampere Hour (mAh) Calculator?

To convert energy (Kilowatt Hours) to battery capacity (Milliampere Hours), you'll need:

  • Energy (kWh): The amount of electrical energy you want to store or convert
  • System Voltage (V): The operating voltage of your battery system
  • Conversion Efficiency: Accounts for energy losses in the system:
    • 85%: Typical real-world conditions with losses
    • 90%: Good operating conditions with minimal losses
    • 95%: Optimal conditions with very low losses
    • 100%: Theoretical maximum (not recommended for practical calculations)

Understanding kWh to mAh Conversion

Converting between energy (kWh) and battery capacity (mAh) involves several key concepts:

  • Basic Formula: mAh = (kWh × 1,000,000) ÷ (Voltage × Efficiency)
  • Conversion Steps:
    • 1 kWh = 1000 Watt-hours (Wh)
    • Watt-hours to Ampere-hours: Wh ÷ Voltage = Ah
    • Ampere-hours to Milliampere-hours: Ah × 1000 = mAh
  • System Considerations: Higher voltage systems require less current for the same power

Factors Affecting Battery Capacity

Several factors can impact the actual usable capacity of your battery system:

  • Temperature Effects:
    • Cold temperatures reduce available capacity
    • High temperatures may increase capacity but reduce lifespan
    • Optimal range: 20-25°C (68-77°F)
  • Voltage Considerations:
    • Higher voltage systems generally have better efficiency
    • Lower voltage systems require larger current capacity
    • System voltage affects wire gauge requirements
  • System Design:
    • Series connections increase voltage
    • Parallel connections increase capacity
    • Balance between voltage and current capacity needed

Common Applications and Sizing

Different applications require different energy storage configurations:

  • Portable Electronics:
    • Smartphones: 10-20 Wh (3.7V, 2700-5400 mAh)
    • Laptops: 40-100 Wh (11.1V, 3600-9000 mAh)
    • Power banks: 37-74 Wh (3.7V, 10000-20000 mAh)
  • Energy Storage Systems:
    • Home batteries: 5-15 kWh (48V systems)
    • Electric vehicles: 40-100 kWh (400V systems)
    • Solar storage: 10-30 kWh (48V systems)

Frequently Asked Questions (FAQ)

General Questions

What's the difference between kWh and mAh?

Key differences between these units:

  • kWh measures energy (power over time)
  • mAh measures charge capacity
  • Conversion requires voltage consideration
  • kWh is voltage-independent, mAh is voltage-dependent
Why is voltage important in the conversion?

Voltage affects the conversion because:

  • Same energy at different voltages requires different current
  • Higher voltage means lower current needed
  • Affects system efficiency and wire sizing
  • Determines battery configuration needs
How do I choose the right battery voltage?

Consider these factors:

  • Application requirements
  • Safety considerations
  • Available space
  • Cost constraints
  • Efficiency needs

Technical Questions

How does efficiency affect capacity?

Efficiency impacts actual capacity through:

  • Energy conversion losses
  • Internal resistance effects
  • Temperature-related losses
  • System component losses
What affects conversion efficiency?

Major factors include:

  • Battery chemistry
  • Operating temperature
  • Charging/discharging rate
  • System components quality
  • Maintenance practices
How do I calculate system requirements?

Follow these steps:

  • Determine energy needs in kWh
  • Choose appropriate system voltage
  • Calculate required capacity in mAh
  • Add safety margin (20-30%)
  • Consider future expansion needs

Safety and Implementation

What safety measures should I consider?

Essential safety considerations:

  • Proper ventilation systems
  • Appropriate circuit protection
  • Correct wire sizing
  • Temperature monitoring
  • Regular maintenance checks
How do I ensure proper system sizing?

Follow these guidelines:

  • Calculate peak power requirements
  • Consider duty cycle
  • Account for efficiency losses
  • Include safety margins
  • Plan for future expansion
What maintenance is required?

Regular maintenance includes:

  • Capacity testing
  • Connection inspection
  • Temperature monitoring
  • Efficiency verification
  • Safety system checks