Mohammad Jafari - Energy Faculty, Material and Energy Research Center (MERC), Tehran, Iran,
Hossein Ghadamian - Energy Faculty, Material and Energy Research Center (MERC), Tehran, Iran,
Sepehr Yousef Beigi - Energy Faculty, Material and Energy Research Center (MERC), Tehran, Iran,
Leila Seidabadi - Energy Faculty, Material and Energy Research Center (MERC), Tehran, Iran,

Since the main part of an off-grid system is its storage system (battery), the requirement to examine the State of Charge (SoC) of the storage system is particular importance. Hence, two models of commercially available Pulse Width Modulation (PWM) and Maximum Power Point Tracker (MPPT) charge controllers are applied in the off-grid systems in order to charge the storage system. In this study, by a quantitative and qualitative review of the two mentioned charge controller, it will be possible for the user to have the appropriate selection to supply the energy requirement. As a research achievement, the rate of charge in the PWM model was higher than MPPT with the ratio 1.25. However, the energy delivered to the battery charge in the MPPT model was 31% better than the PWM model. Furthermore, the photovoltaic (PV) panel performance in the MPPT model is increased about 2% compared with the PWM model. This research also issues that the use of MPPT controller charging is properly operated for low capacities in the off-grid systems, reversely, the PWM charge controller is more appropriate for high capacities of this kind of systems.

State of Charge (SoC), Charge capacity, Rate of charge, Storage system, Photovoltaic (PV) panel performance.