Applications, which were traditionally run on desktop computers, now need to be ported on low power handheld devices. The advent of multi-core embedded processors has brought along new challenges for embedded system design. This paper presents an efficient, battery aware, code partitioning technique for a text to speech system, which is executed on a multi-core embedded processor. The system achieves significant performance improvements both in terms of execution time as well as battery lifetimes. The mentioned technique provides a new paradigm for battery aware embedded system design which can be easily extended to other applications.