Choosing an ultra power-saving mode is an effective way to keep a device running at low battery levels. Manufacturers market this feature under different names, but the principle is the same: limited functionality in exchange for extra hours of battery life.
These modes generally limit screen brightness, resolution, and contrast. Other common strategies are disabling sensors such as GPS and restricting connectivity, CPU speed, and available apps. Given the limited functionalities, consumers may only want to choose this option when there is a great need to preserve battery life.
Samsung was one of the first companies to introduce the ultra power-saving mode on its Galaxy S5, announced at the 2014 Mobile World Congress. Sony announced its STAMINA Mode around the same time, and HTC followed shortly with the Extreme Power-Saving Mode.
One year later, Android 5.0 Lollipop was released with a battery-saving mode that became an Android standard. Yet, many manufacturers deliver new tactics. Apple's power-saving feature, Low Power Mode, is automatically activated when the battery reaches 20%. According to the company, it provides an extra three hours of battery life.