Are you experiencing battery life issues with your iPhone? Here are a few things to check on that may improve your battery performance.
Turn off background app refresh
This is where the Background Activity information, found on your phone's battery settings screen, comes into play. These apps are in action even when you're not using them.
Take Facebook, for example. Social media apps refresh in the background so they can notify you who liked what, when, etc. In the last week, my Facebook app used 17 minutes of background data. It may not seem like a lot, but effects are cumulative, and plus, I don't care much about the expediency of my Facebook interactions.
Unless you're in a situation where time is of the essence (perhaps you rely on notifications in your professional life) you probably can turn off most apps' background activity. To do so, navigate to Settings > General > Background App Refresh. There, you can toggle all of them off at once, or one app at a time.
Turn on Low Power Mode
When your iPhone issues a 20-percent or 10-percent low battery warning, there are options to dismiss the notification or turn on Low Power Mode.
Low Power Mode reduces or disables Hey Siri, Mail fetch, background app refresh, automatic downloads and some visual effects. It's a way to cut off your phone's non-essential features to make your battery last longer.
If you know you have a long day ahead, there's no need to wait for a low battery warning to turn on Low Power Mode. Turn it on and off under Settings > Battery > Low Power Mode.
Remove unwanted widgets
iOS 10 introduced a Widgets screen, which is visible when you swipe left to right from the lock screen. By default, you'll see widgets like calendar events, news items and weather.
Your phone does work to keep those widgets updated. Remove the ones you don't care about, so your phone's resources don't go to waste.
To change them, scroll down to the bottom of the Widgets screen and tap the round "Edit" button. You'll see an "Add Widgets" screen, where you can add and remove widgets as needed.
Adjust display settings: Dim screen, Auto Brightness, Raise to Wake, Auto Lock
Under Settings > Display & Brightness, see where you can conserve some power.
By default, Auto-Brightness is set to on, with the Brightness toggle set somewhere in the middle. We recommend keeping Auto-Brightness on, as it will prevent your display from being overly bright for your surroundings. You can also move the Brightness toggle a little bit lower, and your phone's auto features will skew a little bit darker. Even if the difference is minor, you'll still conserve battery.
Raise to Wake is another iOS 10 feature that can be turned on and off. When turned on, it offers easier access to notifications: The lock screen appears when you pick up the phone, without pressing any other buttons. It's nice (and non-wasteful) if your phone is on your desk most of the time, but if it's in a bag or pocket, the lock screen might be turning on with every jostle. To preserve battery, turn this feature off.
Similarly, Auto Lock controls how long it takes for your screen to lock between uses. The default is one minute, but it can go as high as "Never" or low as 30 seconds. Keep it as low as you're comfortable with. (Note: when your phone is in Low Power Mode, auto-lock is restricted to 30 seconds.)
Turn off "Ask to Join Networks" and Bluetooth
Searching for new Wi-Fi networks might be a boon to your cellular data plan, but it's a battery-intensive function. It's also a useless one if you're not expecting to be able to sign into Wi-Fi. Turn off this setting under Settings > Wi-Fi > Ask to Join Networks.
If you do turn this setting off, you'll have to manually search for and select Wi-Fi networks you wish to join. Return to Settings > Wi-Fi to find networks nearby.
You can also turn off Bluetooth if you're not using it. Your phone uses Bluetooth to communicate with all kinds of wireless accessories: Fitness trackers, wireless headphones, smart home appliances, etc. But if you don't have any of these, save battery and turn off Bluetooth either through settings or the Control Center.
Go to Settings > Bluetooth, or in 3D Touch devices, a deep press on the settings home screen icon launches a Bluetooth shortcut. Or, swipe up from the bottom of your iPhone to view the Control Center, and tap the Bluetooth icon (an angular "B") to turn it on and off.
Use Location Services, Spotlight Search and notifications selectively
Turning off Location Services is similar to turning off Background App Refresh. In many cases, restricting Location Services to when an app is in use will keep your battery usage at an appropriate level without affecting the ways you use your phone. View your apps and adjust Location Services under Settings > Privacy > Location Services.
Spotlight Search is a sometimes-handy feature, but a lot of iPhone users don't even know about it – it's therefore an ideal candidate for turning off. Spotlight Search allows you to search the contents of your iPhone by long-tapping and dragging downward on any home screen page.
In order to keep Spotlight Search effective, your phone needs to constantly re-index its contents, which takes processing power and battery. If you don't use it, turn it off (In iOS 10 under Settings > General > Spotlight Search. In iOS 11 under Settings > Siri & Search.)
As far as notifications go – you've probably already limited your notifications based on their sheer annoyance alone. However, bear in mind that constant notifications stress your battery as well, so there's all the more reason to cull the influx. Under Settings > Notifications, you can dial in the notifications you'd like to see.
Avoid dynamic & perspective zoom wallpapers
Subtle animations in the wallpaper on your lock screen and home screen are fun to see, but totally unnecessary. If battery life is a priority, make sure they're turned off. Go to Settings > Wallpaper > Choose to select wallpaper images and make sure they're set to "still."
Minimize exposure to extreme temperatures
iPhones – and many other rechargeable devices – contain Lithium-ion batteries, which have important benefits for personal electronics but a few drawbacks as well. One of those drawbacks is diminished capacity in cold temperatures.
There's not much you can do about a wintery climate, but if you remember to keep cold exposure to a minimum, your phone will last much longer. Stash it in an internal pocket and minimize usage when you're outdoors, or consider getting a case that provides some insulation. Recommended operating temperatures are between 0º and 35º C (32º to 95º F).
Strategic use of Airplane Mode
When in Airplane Mode, your phone does not send or receive any signals. Of course, this dramatically limits its functions, but it does extend the battery life. Consider switching into Airplane Mode when tuning into offline music, videos or reading. Switching into Airplane Mode while charging your device may also help it to charge slightly faster, even if it's only because it's prevented from undergoing other battery-draining functions.
Do you have an iPhone 6S?
If you have an iPhone 6S with insurmountable battery issues, it could be defective. Apple has admitted that certain iPhone 6S phones, manufactured between September and October 2015, may have a known battery issue. To see if your phone falls under this umbrella, enter its serial number through this Apple Support page. You may be eligible for a free battery replacement.