This Mobile Ad hoc NETworks (MANETs) is gaining importance because of their flexibility, mobility and ability to work with a limited infrastructure. In multi-hop wireless network, proper utilization of battery power is very much necessary to maintain network connectivity. In order to overcome the network from inefficient routing problem, this paper presents different energy efficient routing protocols like AODV (Ad hoc On-demand Distance Vector), DSR (Dynamic Source Routing) and ZRP (Zone Routing Protocol) for mobile ad hoc networks. In this paper, efforts are on methods to reduce the power consumption in communications between ad hoc network nodes.