Application of Peukert's Law in Supercapacitor Discharge Time Prediction

This paper studies the application of Peukert's law in predicting the supercapacitor discharge time during a constant current discharge process. Originally developed for lead-acid batteries, Peukert's law states that the delivered charge increases when the discharge current decreases. Recently, it is revealed that this law also applies to supercapacitors when the discharge current is above a certain threshold. This paper examines two application scenarios in which Peukert's law is utilized to predict the supercapacitor discharge time. Extensive experiments are performed using three supercapacitor samples with different rated capacitances from different manufacturers at various voltages. Results show that the prediction error is significantly reduced when the supercapacitor nominal charge and Peukert constant are properly determined and therefore demonstrate the effectiveness of Peukert's law in improving the prediction accuracy.