Electrical energy management in industrial systems is a challenge and the use of battery energy storage systems (BESS) may be a promising alternative. The proper sizing and definition of optimal charging and discharging strategies of the BESS are crucial aspects to ensure the efficiency and economic viability of the project. The objective of this work is to develop a method for BESS sizing and management targeting the minimization of energy costs in industrial systems. The proposed method was developed in Matlab and makes use of OpenDSS and genetic algorithm for optimization. The simulation considers the load profile, in-house generation, the cost and other characteristics of the batteries, variable energy tariffs and load growth through the years. The simulations performed prove the effectiveness of the method and indicate that the economic viability of investing in BESS is still a challenge, mainly due to the high cost of purchasing this equipment. Therefore, a sensitivity analysis of the price of batteries was performed in the case studied.