Experimental determination of Equivalent Series Resistance of a supercapacitor

Abstract

The synergy between batteries and capacitors has been growing, to the point where supercapacitos may soon be almost as indispensable to portable electricity as batteries are now. One very important parameter of a supercapacitor is the Equivalent Series Resistance (ESR). The energy that can be stored in a supercapacitor depends on ESR, so we intend to measure that parameter. Our tests were made on a 350F supercapacitor, 14V, produced by Econd Ltd. We have two methods: the first consist in evaluating ESR by constant current discharge, and the second method consists in a dynamic discharge cycle at a constant current. After measurements and some mathematical evaluations a real value of ESR is proposed.