Thesis (MSc.) - Cyprus International University. Institute of Graduate Studies and Research Electrical and Electronics Engineering Department

Includes bibliography (sheets 56-60)

ABSTRACT
Due to the environmental damage and CO2 emissions of internal combustion engines,
developments in vehicle technology have increased recently. In this context, electric
vehicles are of great importance. Electric vehicles work with advanced battery
technology. Batteries are a storage method that can store electrical energy as chemical
energy and alternately convert chemical energy into electrical energy. The longevity
of the batteries has made electric vehicles more popular. Although there are many
types of batteries, Li-ion batteries are the most widely used. It is preferred more
because of its high energy densities. Many studies and research are carried out to make
these batteries work longer and more efficiently.
In this context, Li-ion batteries are discussed in this study. Cells were compared with
each other by conducting a comprehensive experiment. Due to the different types of
such batteries, 2 different Li-ion battery cells, which are the most widely used in this
study, were used in the experimental environment. The first is LG 21700 and the other
one is Boston Swing 5300.
With the help of Skyrc D100 V2 charger/discharger, the cells were charged at 1A, 5A,
and 3A respectively, and discharged at 1A, 1.5A, and 2A. During the operations,
temperature, internal resistance, current, voltage, and capacity values were measured
and the results were obtained with the charger master software. With the results
obtained, a detailed capacity and Soc calculation have been made to understand
whether there is any loss. As a result of the measurements and calculations, it has been
observed that the LG 21700 battery cell is more efficient in terms of performance.
Keywords: Electrical vehicle, lithium-ion, battery cells, cylindrical cell, SOC,
capacity, internal resistance, charge, discharge.