In this paper, a cooperative multi-agent system (MAS) is presented for active and reactive power sharing in microgrids through a coupling of distributed control and communication techniques. Due to the natural intermittency of wind and solar, and limited capacity of battery storages, it is essential to manage proper power sharing to ensure the supply-demand balance. In order to optimally utilize of battery storage capacity, this paper emphasizes the power regulation from power electronic inverter interfaced battery storage units. A benchmark low voltage (LV) microgrid is considered and the MAS framework is developed through the well-known graph theory to enable a communication link among the controllable battery inverters where each agent is considered to be embedded to the battery inverter control unit. An optimal linear quadratic regulator (LQR) is designed within a distributed envelop to regulate the power injections into the system from the battery inverters. The consensus of intelligent agents is achieved through the information exchange among the controllable battery units.