Beware of location services
Many apps on iPhone and Android use “location services” to, say, tag status updates with GPS data (“We’re at Disney World!”) or find good deals in your immediate area. This can reduce battery life, so always keep track of it. You can tell if an app is using location services by looking out for a small arrow on the top of your menu bar.
Watch for push notifications
How much battery life is drained by push notifications—those app-specific messages that pop up on your lock screen from time to time? That’s up for debate, but consider this: Each time your phone receives a notification from the network, it lights up and, depending on your settings, vibrates or makes a noise, too. That all takes a toll on your battery, especially if you receive a lot of updates. Toggle push notification options in your settings screen or within the apps themselves to remove all but the vital stuff.
Use a black (or very dark) wallpaper
If your phone uses an AMOLED display—many popular Android devices do, though the iPhone notably does not—each pixel on the screen takes a little bit of power to “light up.” As such, the more black pixels you can get on your screen, the better. Set a dark wallpaper as your default, and try using dark themes on apps when possible.
Use ‘Airplane Mode’
Your iPhone or Android device will always try to connect to a cellular network when possible, which can put a strain on your battery if you’re in an area with limited (or no) service. Switching on Airplane Mode in Settings will stop this from happening—just know that you won’t be able to make or receive calls while it’s toggled on.
If you’re on an Android device, download the Snapdragon BatteryGuru. Created by Qualcomm, the company behind many top-of-the-line phone processors, the app learns your usage habits and automatically adjusts features on your phone to optimize battery life. The iPhone doesn’t have a direct equivalent, but there are several apps that help you avoid wasting power.
Clear out apps
Even if you’re not using an app, it can run in the background and sap battery life from your smartphone. Android devices allow you to “multitask” with apps running behind the scenes—to close them quickly, go to “Applications” within your settings, then tap either the “Manage Applications” or “Running” option. Go down the list and tap any you’re not using, then “Force Stop” or “Stop.” Apps don’t “multitask” on iPhones in the same way they do on Android phones, but the principle’s the same: Unused apps slowly but surely eat away at your battery life. Quickly push the home button on the bottom of your iPhone twice to bring up a row of apps currently open on your device, then hold your finger on one until they all start jiggling: Simply tap the red “minus” icon to close the apps completely.
Lower the brightness
Obvious but easy to neglect: The brighter your screen, the more battery it’s eating. Head over to your settings and turn down the lights to keep your phone running longer.
Turn wi-fi off
Another simple-but-forgettable tip: If you’re not using your smartphone to connect to wireless internet, switch the wi-fi settings to “off.” This will stop your phone from sniffing out networks—even when you think it’s not—thereby saving resources.
Keep it cool
If your phone’s Lithium-Ion battery gets too hot, it’ll discharge its energy faster, and could even degrade the battery’s maximum life over time. Don’t carry it in your pocket if you can avoid it (especially if your pants are tight), and never leave your device sitting in direct sunlight or in a toasty car.
When all else fails, get an extra battery
It’s an obvious solution but perhaps an overlooked one. If your smartphone is an Android or Blackberry device, you can buy an additional battery (or two) to keep charged and slot in when needed. Of course, iPhones don’t let you switch out batteries, but there are a slew of external packs that can juice up your phone in a pinch.