1. Switch Off Your Phone
If you don’t need your phone while you’re sleeping or after business hours, just switch it off. Also turn it off if you are in an area with poor reception because the constant search for service depletes the battery quickly. Plus forget the flight mode on planes; you’re better off switching it off completely.
2. Turn Off Bluetooth and Wi-Fi
Both are power hungry features so disable them when they’re not in use.
3. Switch Off the Vibrate Function
You can switch it off in your phone settings and also set the ring tone volume as low as possible.
4. Avoid Flash Photography
Flashes are powerful and use lots of energy. Same goes for using your phone as a flashlight.
5. Reduce the Screen Brightness
Setting the brightness of the display to the lowest level possible will impact battery life greatly. The same goes for the back light. Reduce your time to one or two seconds to conserve your battery.
6. Close Applications
Shut down apps if they’re not in use, including nonessential apps running in the background.
7. Keep Your Calls Brief
If you can limit your talk time, you will save your battery’s life.
8. Avoid Games, Videos, Pictures and Internet
I know it sounds very restrictive, but those will suck up your power! Also avoid chatting online and any form of videos.
9. Avoid Free Applications
Why? Because free apps have lots of advertising banners, right? Those not only use your battery, but they could potentially harm your phone.
10. Don’t Leave Your Phone Cooking in the Sun
Makes sense. Do not leave your phone (or dog and kids!) in a hot car or anywhere with hot temperatures. There is an optimum temperature range cell phones function at.
11. Avoid Animated Backgrounds
They look cool, but any animated pictures or wallpapers will drain your battery faster than a normal picture.
12. Black Screens are Better than White
Black screens use less power than white, I don’t know why but it’s true. So go with a nice textured black screensaver.
13. Check Your Email Settings
Every time you are receiving an email on your phone, you lose a little battery. Uncheck the automatic box in your phone settings.
14. Run it Down
Don’t stretch your battery by charging it before it fully discharges of its power. Run it down completely before recharging.
15. Turn Off the GPS
GPS uses battery power like no other. Try to use it only when you really need it.
16. Turn Off Notifications and Syncing
Notifications and background syncing aren’t crucial to use your phone, but the constant updating and displaying of messages consumes a good deal of energy.
17. Update Your Apps Regularly
Not always the case, but regularly updating your apps so you have the most current version will utilize less power.
18. Check the Size of Your Apps
After you've plugged your phone into your computer, click on the apps. Beside each of them will be some information included the app’s size. Uninstall the ones that are too big for your phone’s memory and your battery.
19. Purchase an External Battery
Perhaps the most obvious of all suggestions but (again) during a long trip, having a spare battery will be the safer solution.
I’m not asking you to use your smartphone only for brief calls with a dark screen! But in the situation of a long flight, a day at the beach, or away from a power source, you will need to know how to save your phone’s battery and these tips will be part of your survival kit.