Dynamic model of a lead acid battery for use in a domestic fuel cell system

• Published in: Journal of power sources Vol. 161; no. 2; pp. 1400 - 1411
• Main Authors: Dürr, Matthias, Cruden, Andrew, Gair, Sinclair, McDonald, J.R.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 27.10.2006; Elsevier Sequoia
• Subjects: Applied sciences; Battery; Direct energy conversion and energy accumulation; Dynamic model; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Lead acid; Lead acid; Dynamic model; Battery; Lead acid batteries; Temperature dependence; Secondary cell; Discharge charge cycle; Electric discharge; Open circuit voltage; Simulation; Storage capacity; State of charge; Mathematical model; Self discharge; Fuel cell; Electrical characteristic
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2005.12.075

This paper presents a review of existing dynamic electrical battery models and subsequently describes a new mathematical model of a lead acid battery, using a non-linear function for the maximum available energy related to the battery discharge rate. The battery state of charge (SOC) is expressed in a look-up table relative to the battery open circuit voltage (VOC). This look-up table has been developed through low discharge experiments of the battery modelled. Further, both the internal resistance and self-discharge resistance of the battery are subsequently expressed as functions of the open circuit voltage. By using an electrical model with these characteristics and a temperature compensation element to model different rates of charge and discharge, a relatively simple and accurate battery model has been developed. The new model takes into account battery storage capacity, internal resistance, self-discharge resistance, the electric losses and the temperature dependence of a lead acid battery. It is shown in this paper how the necessary parameters for the model were found. The battery modelled was a Hawker Genesis 42 Ah rated gelled lead acid battery. The simulation results of the new model are compared with test data recorded from battery discharge tests, which validate the accuracy of the new model.