This paper presents a comprehensive analysis of the power consumption characteristics of an autonomous service robot across different operational scenarios. The study investigates the discharging profile of a 14.8V 4-cell 10,000mAh LiPo battery, providing insightful observations on the relationship between the State of Charge (SOC) and internal resistance, alongside voltage dynamics during discharge. The results indicate an inverse relationship between the SOC and the system's internal resistance, and a consistent voltage decrement corresponding to SOC. Furthermore, the energetic impacts of various robot components during the Powering On Procedure and Teleoperation and Navigating Procedure are detailed, identifying critical components contributing to high energy consumption. The paper suggests an autonomy duration of approximately 3.5 hours for the electrical system and 2 hours of continuous movement. The study provides a basis for optimizing energy efficiency in autonomous service robots.