What is the primary function of batteries in laptops?

The primary function of batteries in laptops is to allow for longer battery run time. When using a laptop, the battery serves as the main power source when the device is not plugged into an electrical outlet. A better battery can enable a laptop to operate for extended periods, providing convenience and portability to the user. This function ensures that users can work or enjoy entertainment without being tethered to a power source, which is essential for mobile computing.

While providing a constant power supply is also a role of the battery, the emphasis on run time highlights the significance of battery efficiency and capacity in enabling laptop usability away from power outlets. Enhancing audio capture capabilities and visual indicators do not relate to the core functionality of a laptop's battery, as these tasks are typically managed by other components within the device.