The battery pack provides the required power supply for the Arduino, motors, and sensors. Depending on the design, a 9V battery or a 12V rechargeable pack is commonly used. The choice of battery affects the runtime and efficiency of the robot. Li-ion batteries are preferred for lightweight and longer life, while AA battery packs are low-cost options. In the Line Following Robot, the battery ensures consistent voltage to prevent sudden resets or performance drops. A properly managed battery pack allows longer operational time, making it possible for the robot to perform reliably during practical demonstrations and competitions.