iOS 9 has some terrific new features, and a couple of them are designed to extend the battery life of your iPhone. The first feature is called Low Power Mode. Low Power Mode temporarily lowers power consumption by stopping mail fetch, background app refresh, automatic downloads. It also reduces or turns off some of iOS 9's visual effects.
The second feature conserves battery power by letting you put your iPhone face down on a surface to stop the screen from lighting up when you get a notification. Put your iPhone down face up and the screen will light up as usual.
In this tip I'll show you how to enable Low Power Mode manually in iOS 9 for the times when you want to use the lowest amount of power possible on your iPhone.
How to enable Low Power Mode in iOS 9
Enabling Low Power Mode in iOS 9 is quick and easy. Just follow these steps to do it:
1. Tap on Settings.
2. Tap on Battery.
3. Tap on the Low Power Mode switch to turn it to the green (on) position.
And that's it, now Low Power Mode is enabled on your iPhone. You should see that your battery icon at the top of your iPhone's screen is now a yellowish color so you know that Low Power Mode is on. Low Power Mode can get you about three hours or so of additional battery life in iOS 9.
The benefits of Low Power Mode in iOS 9 come at a performance cost
However, nothing in life is free and the benefits of Low Power Mode do come at a cost in terms of performance. When Low Power Mode is enabled, your iPhone's CPU performance may drop as noted by this report on the MacRumors site:
Geekbench 3 has just been updated to work with iOS 9, letting us get a more detailed look at how Low Power mode works and how much it throttles an iPhone's CPU performance when activated.
Without Low Power mode activated, an iPhone 6 Plus scored 1606 on the single-core processor test and 2891 on the multi-core processor test. When Low Power mode was turned on, the same iPhone 6 Plus scored 1019 on the single-core test and 1751 on the multi-core test, suggesting there's a significant performance reduction when Low Power mode is enabled to save as much battery as possible.
Results were similar on an iPhone 5s, with performance reduced by about 40 percent. We saw single/multi-core scores of 1386/2511 without Low Power mode and scores of 816/1405 with Low Power mode turned on.
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