The increasing trend of connecting local distributed generation units to the grid has unlocked new economic opportunities for owners. This is supported by the ongoing development of energy storage technologies, especially battery based systems. In practice, battery storage systems typically operate based on control algorithms where tariff structures and future generation and load profiles are not taken into account. This paper investigates the results of a case study for a microgrid using a proposed optimization model which minimizes cost by considering an import/export tariff structure. The effect of changing time resolution related to variations in demand and generation is examined, and the model assesses economic considerations related to operational capabilities of the battery energy storage.