Part of the latest iOS 9 update is a new feature called Low Power Mode — and it might just be one of the most useful updates for the iPhone.

In its description, it says that turning on the Low Power Mode will temporarily reduce power consumption until you get the chance to charge your iPhone again. Power-draining features such as mail fetch, automatic downloads, background app refresh and some visual effects will be turned off automatically, instead of having the need to turn them off one by one, reported Bustle.

To activate the feature, users will have to go to iPhone Settings>Battery>Low Power Mode. Users can also opt to easily ask Siri to switch it on, reported Sugarscape.

It automatically turns on once the battery reaches below 20 percent, and then turns off once the iPhone is charged back up above 80 percent. When it is off, users will once again experience the full functionality of the iPhone.

Apple has not provided data on how much battery life will be saved, but a test found that it could last 1.43 times longer with the help of Low Power Mode. That means it can raise the number from 12 to 17 hours, reported the Independent.