Mobile Ad-hoc networks (MANET) are being installed in a wide range of applications like military scenarios, rescue operations, data and device networks etc. Many of these networks uses battery operated nodes. A major requirement of these networks is to wisely utilize the battery power of nodes, so that the nodes can actively participate in process of communication for maximum time span without partitioning the network. This will result into maximum network lifetime which is again main goal in ad hoc routing algorithms. To achieve this we proposed an optimized Energy Efficient Hybrid Routing Protocol (EE-HRP) which uses routing strategy that seeks to find the best balance between minimizing the power consumption and evenly using all nodes within the network to avoid early exhaustion of individual node. In EE-HRP we use multiple threshold values for remaining battery power of nodes and assign different role of each node depending on remaining battery power of the node using our Node Energy Monitoring Algorithm (NEMA). Here we also make use of our previously designed algorithm Zone Head Selection Algorithm (ZHSA) which is used to select maximum energy node as Zone Head (ZH). By doing so we prevent nodes from early battery exhaustion which results to increase network lifetime to some extent. The key factor governing the performance of optimized EE-HRP are theoretically analyzed and evaluated. The simulation results are compared with some MANET routing protocols in different network scales, taking into consideration the power consumption. The theoretical analysis and simulation results shows that our proposed optimized EE-HRP reduces total power consumption, reduces end-to-end delay, increases packet delivery ratio and achieves maximum network lifetime.