Choosing an ultra power-saving mode is an effective way to keep the device running at low battery levels. Although specifics differ among manufacturers, models, and operating systems, the notion involves limiting screen brightness, resolution, and contrast, as well as disabling services (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.
Manufacturers give different marketing names to this feature, but the basic principle is the same: limited functionality in exchange for extra hours of battery life. Samsung was one of the first companies to introduce the ultra power-saving mode on its Galaxy S5 flagship, announced at the 2014 Mobile World Congress. At the same time, Sony introduced its STAMINA Mode on the Xperia Z2 flagship, and HTC followed shortly, calling this feature Extreme Power-Saving Mode. One year later, Android 5.0 Lollipop was released with a battery saver mode, and the feature became standard for Android devices.
In Android 5.0, as well as in later versions, the battery saver is configured to turn off location services, vibration, and data syncing. Manufacturers often improve Android's standard battery saver and enhance its capabilities. Apple has a similar feature called Low Power Mode, which gets activated automatically when the battery reaches 20%. The Low Power Mode can increase the phone's battery life with up to three hours.
With our increasing dependence on smartphones to perform our daily tasks, being stuck with a dead phone can be a great inconvenience. Ultra power-saving modes have become standard in the smartphone industry, although the specifics vary, as already mentioned, between operating systems, manufacturers, and even phone models.