A change in the battery indicator’s color to yellow on a smartphone typically signifies that Low Power Mode has been activated. This feature reduces the device’s performance and background activity to conserve battery life. As an example, when the battery level dips below 20% on an iPhone, the system prompts the user to enable this mode, which is visually represented by a yellow battery icon.
The activation of this power-saving feature is important because it extends the usability of the device when a power source is unavailable. It benefits users by allowing them to continue using essential phone functions, such as calls and messaging, for a longer period. This feature became a standard offering on smartphones to address the common user concern of limited battery endurance.