The dynamic characterisation and modelling of lead-acid batteries for electric vehicle applications

  • Clive Morgan

    Student thesis: Doctoral Thesis


    In an effort to increase the available capacity of a lead-acid battery, the effects of pulsed discharge currents as opposed to the effects of continuous discharge currents on the battery were investigated, for a wide range of frequency, mark/space ratio and peak current of the discharge waveform. It was found that for certain conditions of pulsed discharge, the use of pulsed currents can provide a considerable increase in available capacity when compared to that obtained from using conventional continuous currents.

    In order to increase the efficiency and reduce the time of the lead-acid battery charge, the effects of using pulsed charging currents with ·and without depolarisation discharge pulses interspersed throughout the charging period as opposed to using conventional continuous current charging was investigated. For the tests performed, it was found that pulsed current charging without depolarisation pulses offers no advantages over conventional continuous current charging for three-stage and single-stage charging techniques. The use of pulsed currents with depolarisation pulses was found to be less effective than using conventional continuous current or straight pulsed current charging.

    A model for the cell terminal voltage and state-of-charge of the battery is derived from the results of an extensive series of tests performed by the author. In this writing for the first time a model accurately accounts for the dependence of recuperation, regeneration and wide variations in the discharge rate on the temperature of the electrolyte and the effects of these factors on the terminal voltage and state-of-charge. Additionally, for the first time a comprehensive model for use with pulsed discharge currents is derived. The models were tested under dynamic conditions of battery operation and were found to be able to predict battery state to a high degree of accuracy, and were also found to be more accurate than existing models.
    Date of AwardApr 1985
    Original languageEnglish
    Awarding Institution
    • Polytechnic of Wales

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