Renewable energy sources (RES), such as photovoltaics (PV) and wind turbines have been widely applied as alternative energy solutions to address the global environmental concern and satisfy the energy demand. The large-scale amalgamation of intermittent RES causes reliability and stability distress in the electric grid. To mitigate the nature of fluctuation from RES, a battery energy storage system (BESS) is considered one of the utmost effective and efficient arrangements which can enhance the operational flexibility of the power system. This article provides a comprehensive review to point out various applications of BESS technology in reducing the adverse impacts of PV and wind integrated systems. The key focus is given to battery connection techniques, power conversion system, individual PV/wind, and hybrid system configuration. The application of BESS is categorized into three areas, active, reactive, and active-reactive power features. The key findings of the existing research of BESS application are summarized and discussed along with several simulation results. By taking a thorough review, this article identifies the key challenges of BESS application including battery charging/discharging strategy, battery connection, power conversion efficiency, power converter, RES forecast, and battery lifetime and suggests future research directions that could be explored during the design, operation, and implementation of BESS technology in the power system.