Battery Capacity Calculator

Calculate battery capacity in Ah and Wh for optimal power storage

Battery Capacity Calculator

Compliant with IEC 61960 Battery Standards

Results:

Capacity (Ah): 0.00

Energy (Wh): 0.00

Energy (kWh): 0.00

How to Use the Calculator

From Power & Time

  1. Select "From Power & Time"
  2. Enter battery voltage
  3. Input power consumption in watts
  4. Specify required runtime in hours
  5. Set system efficiency percentage

From Current & Time

  1. Select "From Current & Time"
  2. Enter battery voltage
  3. Input current draw in amps
  4. Specify required runtime in hours
  5. Set system efficiency percentage

From Energy Storage

  1. Select "From Energy Storage"
  2. Enter battery voltage
  3. Input energy storage in Wh
  4. System efficiency is applied automatically

Battery Capacity Fundamentals

Amp-Hours (Ah)

Amp-hours measure the charge capacity:

  • Current × Time = Capacity
  • Higher Ah = Longer runtime
  • Voltage independent measurement

Watt-Hours (Wh)

  • Energy storage capacity
  • Voltage × Ah = Wh
  • Direct power consumption comparison

Key Formulas:

Capacity (Ah) = (Power × Time) / (Voltage × Efficiency)

Energy (Wh) = Voltage × Capacity (Ah)

Runtime = Capacity (Ah) / Current Draw (A)

Calculation Formulas

From Power:
Ah = (P × t) / (V × η)

From Current:
Ah = I × t / η

Energy Storage:
Wh = V × Ah

Example Calculation

12V Battery System:

Power: 100W

Runtime: 5 hours

Efficiency: 85%

Ah = (100W × 5h) / (12V × 0.85) = 49.02Ah

Wh = 12V × 49.02Ah = 588.24Wh

Capacity = 49.02Ah | Energy = 588.24Wh | kWh = 0.588kWh

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