There are few things that could be causing battery drain so quick on your Nokia Lumia Phones
Just follow the steps below to boost your Lumia's Battery Life

1) Disable NFC
Near Field Communication (NFC) is a new technology that allows users to send files to each other by just Tapping there phones against each other or placing them in close proximity
According to top reviews this Feature drains battery and causes the phone to begin to warm up at the top, Because its set to ON on most Lumia Phones.

How to turn off NFC on a Nokia Lumia 920
 You won't find an "NFC" option on the 920. This feature is called "tap+send" in the system settings. So navigate to System->Settings->Tap+Send,  there you will finally see it described as "NFC Sharing." Simply turn this feature off and you have disabled NFC on your 920.

2) Nokia Drive
Nokia Drive+ Beta running in the background, Nokia Drive is an offline GPS system, You can turn off this app's ability to run in the background by going to Settings, swipe over to the Applications option, then select "Background tasks." There you can "block" this app's ability to run in the background.

3)Close Unwanted Tasks/Apps
Close unwanted / Unused apps or tasks like Bluetooth, Wifi ect
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WITH ALL THIS PUT IN PLACE YOUR NOKIA LUMIA BATTERY SHOULD LAST LONGER

Note: It has been reported by some that the battery life for the Lumia 920 will increase after about 10 charging cycles.
After almost 3 months of use, I can confirm that the 920 has quite acceptable battery life. It could be due to the fixes above or going through many cycle charges.

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