Wireless platforms are becoming less expensive and more powerful, enabling the promise of widespread use, everything from health monitoring to military sensing. In large scale applications like military surveillance, sensing coverage is essential for target detection and optimization of power consumption is important for lifetime extension of the network. Coverage and long lifetime network are two important factors and challenges for sensor networks. In this paper, we propose a new scheme, named as BECG, which remains the best coverage of the sensing area and energy balanced scheduling for all sensors. It allows nodes to determine when they can switch to sleep mode during operation. The energy efficiency of the proposed scheme is shown by intelligent decisions making. Each node in the network takes decision to turn on or turn off in a distributed manner that results a set of small number of active nodes throughout the lifetime of the network and covers sensing area of interest for target detection. It reduces redundancy, power consumption and increase the lifetime of a network. At first we applied our algorithm for a random topology and then we evaluate the performance of the network by simulation.