Capacitor Energy Storage
Capacitor Energy Storage
A charged capacitor stores energy in its electric field, released rapidly when needed — the basis of camera flashes and power buffers.
The stored energy is E = ½·C·V². where C is the capacitance and V the voltage across it.
Inputs
C := 470 uF=4.7e-04 A^2·s^4/kg/m^2
V := 12 V=12 V
Apply the capacitor energy formula.
E := 0.5·C·V^2=0.03 Nm
Results
The energy scales with the square of voltage, so doubling the voltage quadruples the stored energy. This sets how much charge is available for a burst of current.
Assumptions & limitations
- Ideal capacitor, fully charged.
- Constant capacitance.
- Leakage and ESR neglected.