A Ni-Cd battery model considering state of charge and hysteresis effects

This paper introduces an electrical battery model. Based on a Thevenin circuit with two RC parallel branches, it includes an ampere-hour counting method to estimate the state of charge (SOC) and a novel model for the hysteresis. The presented model can consider variations in its parameters under changes in all of its internal and external variables, although only SOC and hysteresis are considered. Hysteresis consideration does not only allow distinguishing the parameters during charging and discharging, but also during transients between them. The model was designed to be capable of being implemented in online and offline systems. Finally the proposed model was validated for a single Ni-Cd cell, characterized by current interruption method, in an offline system. The validation was also extended to a stack of 210 cells of the same technology. (C) 2014 Elsevier B.V. All rights reserved.