About

Engineers wire capacitors in parallel to increase total energy storage capacity without altering the voltage applied across the terminals. Unlike resistors, capacitors add up directly in this configuration. This creates a larger equivalent surface area for charge storage. This configuration is standard in power supply smoothing and high-energy discharge banks.

A critical, often overlooked constraint is the voltage rating. The entire bank is strictly limited by the component with the lowest voltage tolerance. Exceeding this limit on the bank causes dielectric breakdown in the weakest capacitor, leading to catastrophic failure. This tool aggregates capacitance and identifies the safe maximum operating voltage for the group.

Formulas

The equivalent capacitance for components in parallel is the sum of individual values:

C_total = n∑i=1 C_i

The safe operating voltage is determined by the weakest link:

V_limit = min(V₁, V₂, &dots;, V_n)

Reference Data

Parameter	Symbol	Unit	Parallel Rule
Total Capacitance	C_total	Farads (F)	Additive (C₁ + C₂...)
System Voltage	V_max	Volts (V)	Limited by min(V_rated)
Total Charge	Q_total	Coulombs (C)	Sum of individual charges
Energy Stored	E	Joules (J)	12CV²

Frequently Asked Questions

Standard values (E-series) are cheap and available. Custom large capacitors are expensive and have long lead times. Parallel banks also offer lower Equivalent Series Resistance (ESR) and better heat dissipation.

No. In parallel, the voltage across every component is identical. If you connect a 10V capacitor and a 50V capacitor in parallel and apply 20V, the 10V capacitor will fail. The system is limited to the lowest rating.

ESR (Equivalent Series Resistance) decreases in parallel. Following Kirchhoff's laws, the total ESR is calculated like parallel resistors, resulting in a value smaller than the lowest individual ESR.