Isolated microgrids with renewable energy are an alternative to provide energy service in remote areas or islands. To obtain a viable solution from the economic and environmental point of view it is important to consider the costs and technology of the batteries, since these are one of the main component in an isolated microgrid because they act as a backup to manage the intermittence of solar radiation. In this article the optimization of a hybrid microgrid for the Múcura island in Colombia is analyzed. The optimization model includes battery types and technologies, component cost and fuel cost. The results show the viability of the optimization under different scenarios where a reduction of system costs is obtained.