Adaptive state-of-charge indication system for Li-ion battery-powered devices

Abstract

An algorithm that combines adaptive system with Electro-Motive-Force (EMF) measurements during equilibrium and current measurement and integration during (dis)charge states has been implemented in a real-time SoC evaluation system. During the discharge state also the effect of the overpotential is considered. The overpotential model includes a variety of parameters that are changing during cycling of the battery. Adaptive methods for the battery maximum capacity and for the overpotential model parameters are presented in this paper. The final aim is to predict the SoC and the remaining run-time of a Li-ion battery within 1% inaccuracy under all realistic user conditions. © 2007 WEVA Journal.