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Specap, Inc.
Specap Inc.The Capacitor Experts
Energy Calculator

Energy StorageCalculator

Calculate energy (Joules), charge (Coulombs), and theoretical discharge time. Essential for pulse power, flash circuits, and backup power design.

Calculation Parameters

Enter values to calculate energy

V
W

For theoretical discharge time calculation

Enter capacitance and voltage to calculate

Governing Equations

Energy (Joules)E = ½CV²
Charge (Coulombs)Q = CV
Discharge Timet = E / P
Time Constantτ = RC

Engineering Insights

Energy scales exponentially with voltage (E ∝ V²). For high-density energy storage, increasing operating voltage is often more efficient than increasing capacitance.

Hold-Up Time Design

For power supply applications, useful energy is the difference between initial and minimum operating voltage:

E = 0.5 × C × (V²start - V²min)

Safety Considerations

  • Capacitors above 50V can deliver lethal currents. Always install bleed resistors for discharge.
  • Electrolytic capacitors exhibit dielectric absorption—they can recover voltage after being shorted.
  • Always verify capacitor polarity before connecting power to electrolytic types.

Need High-Energy Capacitors?

Browse our selection of aluminum electrolytic and supercapacitors for energy storage applications.