如何节省 iPhone 电池电量

Once your iPhone’s battery runs out, it’s not much more than a paperweight. And occasionally it has been remarked that Apple’s devices (iPads come in for criticism too) don’t always last as long between charges as we would like.Well, help is at hand. In this giant tips roundup we gather the best power-saving tips and tricks to keep your battery running all day long, whether you’ve got a petite iPhone 8 or a massive iPad Pro. We start with the quick fixes: seven steps for those in battery distress. Below that, you’ll find far more in-depth discussion of the best ways to improve your iPhone or iPad’s battery life, from system-wide settings worth tweaking to third-party apps that you should stop – or start – using in order to save power.

The good news is that over the years Apple has done a lot to improve battery life, while eliminating some of the biggest battery drains, to the extent that you may only need to make a few changes to the way you use your iPhone to preserve battery life. We discuss 4 simple tips and tricks to help your iPhone last longer separately.

How to improve iPhone battery life

  1. To save battery life, start by activating Low Power Mode
  2. Use auto-brightness, Dark Mode and auto-lock to dim/reduce screen output
  3. Identify – and reduce use of – high-drain apps. Go to Settings > General > Battery
  4. Lower audio volume
  5. Cull your notifications
  6. If you can do without them, disable Hey Siri, Location Services and AirDrop
  7. Update to the latest version of iOS

Is your battery faulty?

First things first: let’s check your hardware for faults.

Go to Settings > Battery > Battery Health and you will see a “measure of battery capacity relative to when it was new”. If all is well you will be told that your battery is “currently supporting normal peak performance”.

If your battery is the problem, here’s how to fix a faulty iPhone battery.

Turn on Optimised Battery Charging

Turn on Optimised Battery Charging

Optimised Battery Charging is a new feature in iOS 13, and is activated by default. (If you haven’t done so yet, here’s how to update to iOS 13.) It maximises the lifespan of your battery by minimising the amount of time it is plugged in while fully charged.

Apple explains that Optimised Battery Charging slows the rate of battery ageing by reducing the time that your iPhone spends fully charged.

If you plug in your iPhone before you go to bed at night, it will charge to 80%, and then wait until morning before charging the remainder. It does this by learning your habits, so if it knows you usually get up at 7, it will finish charging just before that. You’ll see a message indicating the time it will finish charging by.

This won’t fix a battery that won’t maintain its charge (and could leave you with an incompletely charged device on the occasions when you wake unusually early), but it should prolong the life of new batteries.

Check Battery Usage

Check Battery Usage

A quick way to check whether there really is a problem with the battery in your iPhone or iPad is to head over to Settings > Battery and wait for your Battery Usage report to load up.

The information on offer has changed in recent versions of iOS. You now get a detailed graph showing Battery Level and Activity. As well as the Last Charge Level and how long it’s been since the iPhone was last charged. You can also view this information over the Last 10 Days.

We’re not sure how useful that data is. The really insightful information is found by scrolling down the page to look at Activity By App, and if you tap that section Battery Usage By App. Here you can see if a particular app is taking a lot of screen time, and crucially if they are responsible for heavy battery use.

In older versions of iOS you could see Usage time (how long you’ve used the device for since the last charge), and Standby (which indicated the total time that’s passed since the last charge). Expect usage to be a lot lower than Standby (unless you’ve been using your iPhone non-stop since unplugging it).

To test your battery in these older versions of iOS, you could make a note of the usage and standby times and then put the device to sleep by pressing the on/off switch at the top. After five minutes check the change in the times.

If your device is working correctly, the usage time should have have gone up by less than a minute, while the standby time should have gained five minutes. If you see more than a minute increase on the Usage time, something is stopping your phone from sleeping and you have a battery drain problem.

Chances are that an app or your email settings are responsible for the drain rather than the battery or the iPhone being at fault.

Use Dark Mode

Use Dark Mode

Dark Mode, which arrived in iOS 13, can make your screen more pleasant to view, and less of a strain on the eyes, if you’re looking at it in a darkened room or at night. But another benefit is that less power will be required to light up the display, making it a good option for the battery-poor.

Go to Settings > Display & Brightness and choose Dark. You can also set this mode to come on at night (choose Light Until Sunset under Options).

Turn down brightness

Turn down brightness

Even if you don’t have iOS 13, you can still turn down the power requirements of the screen.

Lighting the pixels on your device’s Retina display requires a lot of energy. In fact, in testing, excessive screen brightness was the single biggest iPhone and iPad battery killer we found. A few years ago we found that at full brightness, an iPhone 5 lasted 6 hours, 21 minutes while playing 720p video. When we set the screen to half brightness, the same phone lasted 9 hours, 48 minutes. That’s a huge difference.

Luckily you can save some battery life by adjusting the iPhone’s brightness. A quick fix is to turn down brightness using the slider in Control Centre, accessed by swiping up from the bottom of the display. Drag the brightness slider down as far possible, but with a setting that still leaves your device usable.

Apple suggests that the Auto-brightness feature is designed to conserve battery life, but it will do this in moderation. If you’re willing to go further in pursuit of better battery life, you’ll need to use manual settings, and turn off auto-brightness.

Don’t bother quitting apps

Don't bother quitting apps

Next up, let’s dispel a battery-saving myth.

iPhone users tend to quit apps we aren’t using as it seems like a logical way to stop them sucking away at the battery. But apparently, this isn’t such a good idea after all.

Apple Store Genius Scotty Loveless explained back in 2014 that when you close an app you take it out of RAM, which means that when you open it again the iPhone has to load it back into memory. “All of that loading and unloading puts more stress on your device than just leaving it alone,” he wrote.

Indeed, Apple itself – in the person of software chief Craig Federighi – confirmed that closing apps doesn’t do anything for battery life.

And when Tim Cook was asked in an email, “Do you quit your multitasking apps frequently and is this necessary for battery life? Just wanting you to put this controversy to rest!”, Federighi stepped in to reply “I know you asked Tim, but I’ll at least offer my input: No and No.”

Loveless adds that, “unless you have enabled Background App Refresh, your apps are not allowed to run in the background unless they are playing music, using location services, recording audio, or the sneakiest of them all: checking for incoming VoIP calls, like Skype. All of these exceptions, besides the latter, will put an icon next to your battery icon to alert you it is running in the background.”

Turn on Low Power Mode

Turn on Low Power Mode

Low Power Mode reduces overall power requirements and makes your battery last longer. Apple claims the mode will allow you to gain three extra hours of battery life from your iPhone. (iPads, please note, do not get Low Power Mode.)

Low Power Mode isn’t a default option that happens automatically in the background. It will be offered automatically when you hit 20% remaining power: you’ll see a warning flash up and the option to turn on Low Power Mode. Do so and you will notice that the battery indicator turns orange rather than red (or the green it would be if you had plenty of power). The mode will be switched off again automatically when you charge past 80%.

Over on Birchtree they have run tests and found that “on average, my battery was at 17% at midnight in normal mode, but 49% in Low Power Mode.”

If you want, you can enable Low Power Mode without waiting for your iPhone to reach 20%. Go to Settings > Battery and turn on Low Power Mode.

When Low Power Mode is on it will reduce power consumption, stopping Mail fetch, Hey Siri, background app refresh, automatic downloads, and some visual effects. We actually have all those features turned off on our iPhone already, yet Low Power Mode still seems to have an effect.

Update iOS or iPad

Update iOS or iPad

Updating to the latest version of iOS (or iPadOS, on iPads) is generally an all-purpose fix when you’re experiencing minor problems with an iDevice; Apple uses its regular (free) operating system updates to roll out fixes for vulnerabilities, bugs and glitches, and it’s entirely possible that an issue you’re experiencing can be fixed with a simple OS update. This includes battery problems.

iOS 10.2.1, for instance, resolved a known battery/charging issue for iPhone 6, iPhone 6s and the Plus variants of both.

On the other hand, the software update might be your problem. iOS 14.2 caused some users to experience faster than normal battery drain on their iPhones. Read: iOS 14.2 causing iPhone battery drain.

Here’s how to update iOS on iPhone, and here’s how to update iPadOS on iPad.

Switch off Facebook

Switch off Facebook

Facebook has been accused of being a battery hog on the iPhone and iPad in iOS, and even Facebook itself has admitted that the iOS app uses a lot of resources in the background.

A Guardian report in February 2016 claimed that uninstalling the Facebook app can save you up to 15% of iPhone battery life. (Instead, you can access the Facebook website via the Safari app.)

A quick look in your Battery Usage log (Settings > Battery) will reveal how much battery life Facebook is guzzling. Ours has used 26% of our iPhone’s charge in the last 24 hours.

Facebook was also accused of allowing battery drain to occur even if iPhone owners have background app refresh disabled in Settings > General > Background App Refresh. Facebook admitted the fault and then fixed it, but battery drain issues are still plaguing users.

You could delete the Facebook app and just access Facebook through Safari on your iPhone.

While you’re there, take a look at how much battery life your other apps are draining too.

Use Auto-Lock

Use Auto-Lock

While the screen is on, you’re consuming power, so make sure that your iPhone or iPad isn’t awake when you don’t need it to be. If you want to get the maximum battery life, it’s wise to set the Auto-Lock to an ultra-low 30 seconds – an option that has been available since the iOS 9 update.

Venture into Settings > Display & Brightness > Auto-Lock (if you’ve got an old version of iOS, you may see Settings > General > Auto-Lock instead) and set your device to sleep after 30 seconds of inactivity.

This will provide a substantial improvement to battery life over time. If you really want to max out your iPhone’s battery life, try to get into the habit of pressing the Sleep/Wake button at the top of your iPhone as soon as you’ve finished using it.

Disable Wi-Fi

Disable Wi-Fi

If you still need a cellular connection but can live without Wi-Fi, you can disable Wi-Fi by swiping up to reveal Control Centre and tapping the Wi-Fi icon to turn it off (if it’s off, the Wi-Fi icon will be black). This will stop your phone from hunting around for Wi-Fi networks it could join.

There are a few situations where avoiding using Wi-Fi might stop battery drain. If the Wi-Fi signal is poor then your iPhone will require more power to transmit and receive data. Similarly, if you are rarely in a place where you could join a Wi-Fi hotspot then there is little point in the iPhone hunting for one.

However, we wouldn’t recommend using 3G/4G if there is a Wi-Fi network available. There is usually no financial cost associated with using a Wi-Fi network, while you may have to keep within a data allowance as part of your network contact.

Another reason is that your iPhone consumes less power accessing data over Wi-Fi than it does when doing the same task over 3G/4G. This is why Apple frequently quotes different battery life for 3G/4G compared to Wi-Fi, with the the difference sometimes as much as a few hours.

Tap Settings > Wi-Fi and ensure Ask to Join Networks is set to On. This will help you spot open networks to join.

Disable Bluetooth

Disable Bluetooth

If you have Bluetooth on, the chances are you don’t need it. Swipe up on Control Centre to check if Bluetooth is on: if it is you’ll see the icon that looks like a runic B highlighted in white.

Bluetooth is usually left on after an iOS update is installed, so you may not even be aware that it is on. If it is, tap the Bluetooth icon to turn it off. You can also tap Settings > Bluetooth and set Bluetooth to Off.

Bluetooth is considered to be a battery drainer. If you’re not using it to connect to a speaker, headphones, or other accessory, or to use the Continuity features in iOS, then switch it off.

Turn off AirDrop

Turn off AirDrop

One iPhone service that requires Bluetooth is AirDrop. Added back in the iOS 7 launch, AirDrop allows you to transfer photos and other files to and from nearby iPhones with the same feature switched on. Unfortunately, it could be a battery killer, because of the way AirDrop seeks out nearby iPhones to hook up with.

Back in iOS 10 and earlier you could switch off AirDrop in the Control Centre (swipe upwards from the bottom of the screen) and only turn on AirDrop when it’s needed.

Since iOS 11 AirDrop is always on – as long as Bluetooth and Wi-Fi are on. So if you want to turn off AirDrop you could just switch off those features, or by long-pressing on the section of Control Centre where you can access Wi-Fi and Bluetooth, you’ll be able to access AirDrop options and turn it off.

Read about how to AirDrop from iPhone to Mac and Mac to iPhone.

Disable 3G, 4G

Disable 3G, 4G

If you can survive without data but still need to be contactable you could turn off 3G or 4G. Your data connection can be disabled in the Cellular section of Settings. Go to Settings > Cellular (or Mobile Data) and switch Cellular Data (or Mobile Data) to off.

If you have an iPhone that is capable of 4G you may be able to separately turn off 4G here as well. We recommend that you do this if you don’t actually have a 4G contract.

If you aren’t using it then switching off cellular data will increase battery life. This has a benefit over just using Airplane Mode, as you will only disable the cellular data portion of your signal, e.g. EDGE, 3G, 4G, or LTE.

Normally your iPhone receives two signals at once: one for calls and SMS, and one for data. Now it only receives the signal for calls and SMS – which means you are still contactable, you just can’t browse Facebook (unless you can access a Wi-Fi network).

You should also note that, according to Apple Genius Scotty Loveless, the signal strength meter on the iPhone only shows the signal strength for the non-data connection, which means your iPhone could show 2-3 dots but actually have a very poor 3G or LTE connection, thus causing your iPhone to go into heavy search mode.

Turn down the volume

Turn down the volume

It might surprise you but the volume setting affects battery life too, so if you are playing music or other audio from your phone, turn it down using the volume buttons.

Of course you could save battery power by not playing music, or you could switch to headphones, which won’t require as much power as the iPhone’s internal speakers. Note that the music equaliser also takes up a surprising amount of power.

Tap Settings > Music and make sure EQ is turned to Off.

Stop vibrating

Stop vibrating

Head to Settings > Sounds & Haptics and turn off both of the vibrate options, because your device rattling around like crazy when a slew of messages arrives drains the battery like nobody’s business.

There are dozens of annoying jingles you can choose from to announce to the world that someone has just sent you a message without the accompanying vibration.

Tone down visual effects

Tone down visual effects

Assuming you don’t suffer from some kind of motion sickness or balance disorder, the various 3D effects first introduced in iOS 7 might excite you.

These pretty Parallax effects that make your icons and notifications appear to float over the wallpaper might look nice, but they constantly use your iPhone’s graphics processor and are therefore a drain on the battery that you could probably manage without if you were trying to get a last half hour of use out of your iPhone on a long journey home.

One thing you can do is switch to static rather than dynamic wallpaper – the wallpaper, first introduced in iOS 7, that moves around as you tilt your phone. This will cut down the power drain a little. When you set a new Wallpaper, tap where it says ‘Perspective Zoom: On’ to turn it off.

You can also go to Settings > General > Accessibility > and switch on Reduce Motion to temporarily turn off all the parallax effects. Note that this will replace many system zoom effects with cross-fades which don’t look as nice, but might just give you those extra few minutes power that you need.

Avoid games and high-impact apps

Avoid games and high-impact apps

It sounds obvious to say your iPhone’s battery is drained quicker the more you use your phone, but the speed with which it falls from 100 percent to nothing entirely depends on what apps you use.

Some apps burn through your battery much faster than others. Heavy use of the processor and GPU, for 3D games, or the GPS chip, for maps and location-based apps, uses up more energy than reading content in the Books app, for example.

If you play games with rich, detailed visuals, such as Infinity Blade, or 3D racing games like CSR Racing, your iPhone’s battery will be drained quickly. So if you’re away from a charger and waiting for an important call, playing these sort of games is not a good idea if your battery levels are already low.

If you’re on the way home and low on power, reading apps like Kindle or Instapaper won’t drain what’s left of your battery terribly quickly.

However, it probably wouldn’t be a smart move to start playing your favourite TV series, or, worse, the latest 3D gaming blockbuster. In fact, even quite simple games often utilise complex 3D trickery, and so when in the red battery-wise, avoid them entirely.

Minimise camera use

Minimise camera use

Isn’t it always the case that the battery on your iPhone runs out just as you take the perfect shot on a night out with your friends?

If you’re running low on battery you should keep your Camera app usage to a minimum, and definitely avoid using the flash.

Turn off Hey Siri

Turn off Hey Siri

Even Siri can be a bit of a drain on battery life, and the Hey Siri feature in particular should be turned off if you want better battery life. Go to Settings > Siri & Search and make sure Hey Siri isn’t switched on.

Not familiar with Hey Siri? If that feature is enabled, it listens out for the phrase “Hey Siri,” and when it hears it, Siri powers on and prepares for incoming commands. That might sound great (and it is!), but constantly listening out for the magic phrase will have an impact on battery life.

For exactly this reason, Hey Siri used to only work if your device was plugged into a charger, but – due in large part to popular demand – Apple relaxed that requirement in an iOS update. Good news, but something to look out for if battery life is a worry.

Notification Centre

Notification Centre

Similarly, Settings > Notifications might be worth a visit, although there’s sadly no global off switch. If you’re running out of power, editing notification settings for all your apps one by one might actually burn more power than it saves.

Each time a notification is received, the iPhone’s screen lights up and it plays a sound, which uses energy. Every message wakes your device for 5 to 10 seconds, and that can add up, if you get a lot of notifications every day, to a small percentage of your daily battery charge.

We can live without updates about Words With Friends, so it makes sense to turn off notifications for non-critical apps (incidentally, it was the persistent notifications in that app that lead us to delete it in the end).

To stop notifications, go to Settings > Notifications and scroll through the list of apps, looking to see which ones have Notifications turned on.

Tap on each one you’re not interested in, and deselect the Allow Notifications option. Read more about controlling your notifications here.

Remove multiple email accounts

Remove multiple email accounts

Multiple email accounts will consume use of your precious battery life. Try to fold all your different accounts into just the one email service then remove the additionals by tapping Settings > Accounts & Passwords and choosing an account and tapping Delete Account.

In the case of Gmail, for example, you could turn Mail off but keep your Gmail Calendar synced.

Turn off iCloud

Turn off iCloud

Similarly, if you want to make that last bit of juice last longer, turn off anything you don’t need to be synced via iCloud.

iCloud uses a fair bit of data and power, so you can save battery life by turning off unused features. Tap Settings > your Apple ID > iCloud and turn off everything you don’t really use: for example, you may not need your Safari bookmarks to be available on the iPhone.

iCloud backup only works when the phone is plugged in so you can leave that on.

Turn off auto time zone

Turn off auto time zone

The iPhone can automatically update its time depending on where you are in the world. Because the iPhone determines the correct time via Location Services, this uses a small amount of power.

Tap Settings > General > Date & Time and change Set Automatically to Off.

Turn off Location Services

Turn off Location Services

Most of the time it’s not iOS itself that’s causing the iPhone or iPad’s battery to drain quickly, but all the apps that are running on it.

There are a number of apps that utilise location services on your iPhone and they can play their part in draining your battery too. It’s even more frustrating when it’s not obvious why some of them need to know where you are in the first place.

To stop apps from using Location Services, tap Settings > Privacy > Location Services and either turn off Location Services altogether (by tapping the slider beside it), or deselect any apps that you don’t need to access your GPS.

Disable background app refresh

Disable background app refresh

Before iOS 7, if you switched between apps by double tapping the home button, the old app would be put into a frozen state, with limited access to system resources. Since iOS 7 background apps have been allowed to periodically refresh their data. This means when you open the app again, you’ll see the latest updates immediately.

This can be useful in certain circumstances, but most of the time is just wasting processing power and battery juice updating apps that you don’t really care about.

If you want to get the most out of your battery, turning off Background App Refresh will help. Go to Settings > General > Background App Refresh. Here you can turn off Background App Refresh altogether, or prune the list down on an app-by-app basis.

Disable app updating

Disable app updating

Way back in iOS 7, Apple gave us the ability to have apps update without manually telling them to.

This is a useful feature that means apps will always be up to date, but it can be a drain on your battery. Also, some people prefer to update on a case-by-case basis, since occasionally a developer will update an app in a way that reduces user satisfaction.

Luckily, you can stop apps from auto-updating. Switch off automatic updates in Settings > iTunes & App Store, scroll to Automatic Downloads and switch off Updates.

If you decide to leave any of these Automatic Downloads settings on, ensure that the switch for ‘Use Cellular Data’ isn’t turned on if you have limited data allowance (read more about not exceeding your iPhone data allowance).

Show the battery percentage

Show the battery percentage

If you want to keep an eye on your battery level, you may find it easier to see a percentage representation, rather than a bar icon. If you want to see how much charge you have left as a percentage, go to Settings > Battery and activate Battery Percentage. Now you will have a more precise read-out of what life your device has left.

All devices will warn when your battery life hits 20 percent and then 10 percent; also, be mindful that even if your battery has a few percent left in it, your device might automatically shut down anyway, so don’t be doing anything too important when your iPhone or iPad is gasping for breath.

Apple Genius Loveless does warn that some people become so concerned about their battery percentage that they keep turning on their iPhone to check it, and every time they wake up their phone a little bit of power dies.

Note: if you have an iPhone X, XS, XR or 11 you can only see the percentage of battery life left by swiping down from the top right of the iPhone’s screen.

Calibrate

Calibrate

If despite trying all these tips to get more battery life out of your iPhone, you are still finding yourself running out of juice earlier than you think you should – perhaps your iPhone battery is going from 17 percent to 2 percent in a matter of minutes – your iPhone or iPad might need a battery calibration.

Apple recommends that you periodically drain your iPhone or iPad’s battery totally and then charge it up until it’s completely full. That’s down to 0, and up to 100 percent. You should do this at least once a month.

This process, called calibration, helps your device estimate its battery life more accurately. Calibrating your battery will ensure that you know when you need to charge the battery, but the procedure itself doesn’t actually make the battery itself last longer.

Another reason why your phone might exhibit this kind of behavious is if the battery needs servicing or replacing. You can find out if that’s the case by going to Settings > Battery > Battery Health (Beta).

Read more about how to get your battery replaced if it’s losing power.

How much battery life have you got left?

How much battery life have you got left?

Frustratingly, there is no easy answer to this question. In iOS 8 Apple began to allow users to see which apps are the biggest battery drainers and you can of course see the percentage of battery power remaining.

You can also see how long your phone has been running without a charge, and how much of that time you have been using the iPhone, but it can’t tell you how many hours you have left.

This is probably because the amount of battery life remaining is entirely dependent on what you are planning to do with your iPhone. If Apple told you to expect two hours and then you ran a movie on full blast you would probably run out of battery before the movie ended.However, there are third-party apps that can give you some guidance about how much battery life is remaining.

If you search the App Store for Battery Saver or Battery Doctor you will see a number of tools that offer system tweaks, with a particular focus on saving battery life.Expect to see an estimate for how much battery life is left, based on what’s running in the background, and your current system settings. If you perform some of the tweaks suggested by the app, you’ll see this number creep up.

For example, when testing one such app we switched on Airplane Mode we gained about an hour of battery life – the battery life remaining changed from 8hrs, 17mins to 9hrs, 21mins.Tap on Optimize to see a breakdown of how much longer your iPhone could last if you shut down certain services, such as disabling Wi-Fi or GPS, or reducing brightness.

Tap on Remaining for details of how much time you have remaining to do certain tasks, web browsing on Wi-Fi, or web browsing on 3G, talk time, video playback, photo taking, and more.

Should you leave your iPhone plugged in?

Should you leave your iPhone plugged in?

When you get to work do you plug in your iOS devices, so that they’re nicely charged up by the time it’s home time?

In principle this should mean your iPhone (and iPad) always have enough power to get you through the commute home. But could this practice of leaving your iPhone plugged in all the time cause damage to the life of the battery?

There is some debate about this. The iPhone is designed to stop charging its battery once the battery is fully charged, so this should mean that the battery can’t be ‘overcharged’ as such. Apple’s new optimized battery charging seeks to minimise the amount of time the battery spends fully charged.

However, we know from our experience with laptops that have been left plugged in at all times that the ability of the battery to sustain a charge seems to deplete over time.

The best advice is to make sure that you drain your battery down to zero at least once a month if you want to ensure that you get a good life span out of your battery.

Turn your device off

Turn your device off

This one’s a last resort, but if you need an iPhone to survive a weekend or a power outage, and its reason for being powered up is essential communications only, turn the device off when you’re not using it.

First, that’ll stop you being tempted in just having another quick go on Candy Crush; secondly, it’ll also ensure even background tasks aren’t slowly supping power. To turn your iOS device off, hold the sleep button for a few seconds and then drag across ‘slide to power off’.

Note, however, that if you only have a few percent of battery left then your iPhone might not power on again if you turn it off. So switch to Airplane Mode in those circumstances.

Get a battery pack

Get a battery pack

If you still need more battery life after all these tips, you should consider an external battery pack, or a case with one built in. There are many on the market that are worth considering, such as the Moshi IonBank 3K (pictured) that can be used to keep the iPhone running for longer.

Read our roundup of the best battery packs for any iPhone model.