This paper describes system definition of the extended range EV and presents cruising strategy of EV mode and ER mode. Also high voltage battery strategic SOC could be indicated and compared depends on various generator working cycles. A C-segment SUV has been produced and carried out cruising test in order to validate on highway, city and hill climbing road. This paper shows advantages and disadvantages of SOC variation on each road environments and presents the strategies as the cruising test results. On the basis of the test result, this paper suggests future works and research directions for strategy of battery management to extended range EV.