Abstract: A mobile Ad-Hoc network is a collection of wireless nodes that can dynamically be set up anywhere and anytime without using any pre-existing network infrastructure. It is an autonomous system in which mobile hosts connected by wireless links are free to move randomly and often act as routers at the same time. Mobile ad-hoc network have the attributes such as wireless connection, continuously changing topology, distributed operation and ease of deployment. The most important feature of a routing protocol, in order to be efficient for WSNs, is the energy consumption and the extension of the network’s lifetime The distributed nature and dynamic topology of Wireless Sensor Networks (WSNs) introduces very special requirements in routing protocols that should be met. An analytical survey on energy efficient routing protocols for WSNs is provided. Energy efficient routing protocols are classified into four main schemes: Network Structure, Communication Model, Topology Based and Reliable Routing. In this paper, the classification is expanded, in order to enhance all the proposed papers earlier and to better describe which issues/operations in each protocol illustrate/enhance the energy efficiency issues. In this paper we have compared the performance of three MANET routing protocol DSDV, AODV and DSR by using NS-2. DSDV is proactive (Table driven routing Protocol) whereas AODV and DSR share similar On Demand behavior, but the protocol's internal mechanism leads to significant performance difference. A detailed simulation has been carried out in NS-2. The metrics used for performance analysis are Routing Overload, Delivery Ratio, And Average Delay.