Nokia Lumia 928 - How can I prolong the battery life of my Lumia phone?

Save power automatically by tapping Settings > battery saver. When Battery Saver is on, a small heart icon appears over the battery icon, and your phone does not automatically receive mail and calendar updates, update some live tiles, or allow apps to run in the background. 

You can also try the following:

Turn off services and functions that you do not use: 

  1. Close apps you are not using: Long press the back key to see the apps running in the background. Swipe through the app list and tap the X to close the apps that are not needed (Phones with Lumia Amber: Long press the back key to see the apps running in the background. Tap the app to open it and tap the back key to close it).
  2. Switch off location services: Tap Settings > location, and switch Location services to Off.
  3. Switch off Bluetooth: Tap Settings > Bluetooth, and switch Status to Off.
  4. Switch off NFC: Tap Settings > NFC (tap+send), and switch Tap to share to Off.
  5. Stop your phone connecting to your music collection in the cloud: Start Music app, then tap ... > Settings, and switch settings to off.
  6. Check which apps are running background tasks and block the ones you do not need: Tap Settings > battery saver, swipe left, and you will get recent battery usage with app list. From there, you can tap on any app to manage it. (Phones with Lumia Black and Amber, tap Settings, swipe to applications, and tap background tasks. Tap the app you want to block, and tap block).

Change the frequency of certain events:

  1. Change your mail settings to retrieve mail items less frequently: On the start screen, open the mail account you want to modify, tap ... > Settings > sync settings and change the setting for Download new content or set it to manual control.
  2. Set your phone screen to switch off after a shorter time: Tap Settings > lock screen, and change the setting for Screen times out after.

Other tips:

  1. Reduce screen brightness: Tap Settings > brightness, switch Automatically adjust to Off, and switch Level to low.
  2. Change the setting for Nokia Glance Screen: Tap Settings >glance, and switch Glance Screen to Off.
  3. Use double-tap to wake up your phone only when needed: Tap Settings > touch, and switch Wake up to Off.
  4. Set your phone to use 2G (GSM) network only: Tap Settings > mobile network (or cellular) > Highest connection speed.
  5. Switch off WLAN connection: Tap Settings > WiFi, and switch WiFi networking to Off.
  6. Charge your phone until the phone battery level is 100%. To check phone’s battery level, go to Settings > battery saver > Remaining Battery Life.
  7. Use wired headphones, rather than the loudspeaker.
  8. Check that your apps are up-to-date: Start Store, then tap ... > Settings > check for updates. (Phones with Lumia Black and Amber: If there are updates available, tap Updates at the bottom of the Store front page).

If the battery keeps draining fast:

  1. Restart your phone by pressing and holding the Power and Volume Down keys simultaneously until the phone vibrates. Release and the phone will restart. After this operation, you may need to set the date and time on the phone (Settings > date+time).
  2. Out of date or invalid passwords for email and social media accounts affect battery life. Delete and re-create your account profiles by long tapping the relevant account profile in (Settings > email+accounts). If this fails, switch your phone to flight mode and reboot. Then delete your email profile, turn off flight mode and re-create your email. Apply this for all stalled account profiles (Mail Account which is set as Microsoft Account on the device cannot be removed manually).
  3. The battery may be wearing out and require replacing.