MANET (Mobile Ad-hoc NETwork) is a self organizing and self configuring network without the need of any centralized base station. It is a collection of nodes that is connected through a wireless medium forming rapidly changing topologies. MANETs are infrastructure less and can be set up anytime, anywhere. In MANETs, the nodes are mobile and battery operated. As the nodes have limited battery resources and multi hop routes are used over a changing network environment due to node mobility, it requires energy efficient routing protocols to limit the power consumption, prolong the battery life and to improve the robustness of the system.