How Siri Can Get Your iPhone Battery To Last 38% Longer


By Josh Adams

When your iPhone battery dies it’s like having flashbacks to 2006. Nobody wants that. It’s been happening to my 16 month old iPhone 6 constantly. Charging it during the day gets annoying real fast.

I refuse to festoon my iPhone like some 21st century pocket-dwelling Quasimodo with the $99 Apple Smart Battery Case. Honestly I am not making this up, this is a real Apple-made product:

Apple Smart Battery Case

Bulky third party battery cases are also unappealing. The very existence of this type of hardware proves that iPhone battery life is a common problem.

This is how quickly my iPhone battery seems to drain!

So I experimented with Low Power Mode, an option added to the Apple Settings app in iOS 9 (on iPhones only, sorry iPad users!).

Low Power Mode is no great secret. The mere fact that you have read this far means you have likely seen the alert asking if you want to turn Low Power Mode on. It is first shown when your iPhone battery hits 20%. It will reappear if your battery continues to drain without turning it on.

Low Power Mode alert
This is the Low Power Mode alert

With Low Power Mode turned on animation is reduced and apps that request data in the background are restricted. Other features like “Hey Siri” with an unplugged iPhone (on the 6S and 6S+) are also turned off.

Low Power Mode Disclaimer
The warning you get the first time you turn Low Power Mode on.

But the key is that your iPhone still works. You will still get iMessages, app notifications, and emails. Phone calls work fine too (if you’re into using your iPhone for that sort of thing!) Bluetooth devices stay connected. Low Power Mode doesn’t save battery by totally disconnecting your iPhone like the oft-used trick of turning on Airplane Mode.

Apple clearly intends this feature as a stop gap in exceptional situations. It exists to keep your iPhone operational until you can charge it. After it is charged back up to 80%, Low Power Mode is automatically turned back off.

The Trick

Here’s the technique I have been using:

Don’t wait until your battery is low to turn on Low Power Mode. Turn it on when your battery is at 100% and it will last much longer. –TWEET THIS

You can even set yourself a daily reminder to turn Low Power Mode on every morning if necessary.

I have been doing this for several weeks now and am greatly pleased with the improved battery life. It feels almost like I have turned back the clock and have a brand new iPhone battery.

I knew that I probably wasn’t the first person to try it. I googled “Low Power Mode all the time” and discovered that Matt Birchler over at BiteSize Tech had examined this technique in detail. He spent serious effort measuring the power savings and figured that it increased battery life by up to 38%.

In practice I get an extra 1–2 hours of active use per day.


The obvious way to turn on Low Power Mode is to go to Settings -> Battery and toggling the Low Power Mode switch.

The easy way to turn it on is to tell Siri to turn on Low Power Mode.

You can tell at a glance whether Low Power Mode is enabled by the color that is filling the battery in your iPhone status bar. When Low Power Mode is on, it turns yellow.

Notice how the inside of the battery turns yellow when Low Power Mode is on. Thats the easiest way to tell if it is on.
Notice how the color inside the battery turned yellow, indicating that Low Power Mode is on.

There is nothing you can do to prevent Low Power Mode from being turned off once your iPhone hits an 80% charge. However, you get a notification that Low Power Mode is off when that happens. You can then swipe left on the notification from the lock screen to reveal an “Enable Low Power Mode” button. Tapping that turns it on directly from the lock screen.

Re-enabling Low Power Mode from the Lock Screen.

I have had no problems with missing notifications of iMessages or email with Low Power Mode on. Your mileage may vary. It may depend on your backend service for email.


Apple doubtless would not favor this method. Their recommendation would be to turn off background fetch and location services for offending apps by finding the offenders in Settings -> Battery. They are probably right that that’s the best way.

However Low Power mode also turns down your processor power and does some other power-saving tweaks. Plus it has the benefit of being controlled by a single switch and requiring no trial and error.

I am quite sure their second recommendation would be to try a battery case or buy the enormous iPhone 6S+ which has a bigger battery that lasts longer.

But if you want something quick and easy to try, this just might work.

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