Design-Aid Calculators

CAP-XX has three downloadable MS Excel spreadsheets to aid in supercapacitor and pulsed load design. Please note that these spreadsheets are a design guide and should not be regarded as a substitute for the thorough design work required to achieve the best result. They are based on the assumption that the components in the model circuit above are ideal and behave as such. In practice, the effective capacitance available at various frequencies, temperatures and currents (and even at different voltages) may vary. Designers should consult CAP-XX before finalizing their designs.

Fixed Power Spreadsheet (Excel, 1.3MB)
Fixed Current Spreadsheet (Excel, 1.3MB)

The circuit simulated by these spreadsheets consists of a supercapacitor in parallel with a battery (or voltage source with internal impedance). This "hybrid" system is subjected to a load consisting of a constant-current or constant-power drain, plus a repetitive pulse of fixed current or fixed power. These spreadsheets have been updated on 9th Aug 2006. You need to turn “Iteration” on to calculate the steady state response. Please refer to the updated “Read Me First” instructions.

Voltage Decay Simulator Spreadsheet (Excel, 500KB)

The circuit simulated by this spreadsheet consists of a supercapacitor (or capacitor) having a capacitance C and Equivalent Series Resistance (ESR) RC. The supercapacitor is initially charged to a certain voltage and has a load imposed on it, beginning at time t=0. The load, which may be either a fixed current or a fixed power, is present for the duration of the simulation. The simulation runs for a time T.