Cycle Testing of Supercapacitors for Long-Life Robust Applications

This paper presents the final results of a study on supercapacitor lifetime. As long component lifetime is a requirement for many applications, a computer-controlled test rig has been built to validate supercapacitor lifetimes to manufacturer´s specifications. The test rig is also utilized to determine the effect of temperature on supercapacitor parameters and investigate application lifetime. Cycle testing is carried out on individual supercapacitors at room temperature and at rated temperature utilizing a thermal chamber and equipment programmed through GPIB and Matlab. The supercapacitors, under standard testing at ambient and rated temperatures, and application testing at ambient temperature, have undergone approximately ten million, 11 million, and one million cycles, respectively, over two years. The supercapacitors did not experience end-of-life failures but remained within specified operational tolerances. The study was terminated after successfully completing 11 million cycles at approximately 75% DOD at rated temperature. The results demonstrate cycle lifetimes significantly in excess of manufacturer specifications and potential for deployment in long-life robust applications.