This paper presents Mathematical Model and Experiment of Temperature effect on Charge and Discharge of Lead-Acid Battery performance in PV system power supply. To test temperature effect on battery discharge cycles, a temperature range of tropical area from 25 - 60 degrees Celsius in a simulator is set up for testing. This temperature range is normally practical for battery usage. This allows the battery to determine the parameters of the battery quickly and high accurate. A Mathematical Model with MATLAB Program is written and constructed as block diagram using the equations of battery the parameters. By running program, the effects of various parameters are investigated. The results showed that time of discharge the battery is longer. Then, the experiment is set up by battery VRLA 12 V 20 AH. The results confirmed the mathematical model simulations.
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 N. Moubayed, J. Kouta, A. El-Ali, H. Dernayka and R. Outbib, “Parameter Identification of the Lead-Acid Battery Model,” 33rd IEEE Photovoltaic Specialists Conference, Beirut, 11-16 May 2008, pp. 1-6.