My phone's battery life over the past couple of months has been reduced to anywhere from 1 to 5 hours. That means I have to charge my phone 3x in one day plus at night.
Low screen brightness
Email refresh disabled
I have basically turned off all the features that make it a smartphone.
The problem from what I can tell is that my phone is constantly accessing the network. I just did a hard reset so that no apps are running, but as I look at my phone it, the 4G LTE icon at the top shows that data is being sent/received. I have deleted apps. I have disabled apps. I have read the posts online for help.
Of note: this decrease in battery life has coincided with apps and the operating system freezing on a semi-regular basis. This phone, while a good phone, has become unusable.
Lastly, before the upgrade to Jelly Bean (I think?) my phone lasted 1.5 days on 3G.
Since you posted this in the Droid Razr space, I'm assuming that's what you have ... if so, the last update was to ICS (Ice Cream Sandwich).
You may want to install Onavo Count from Google Play; it not only is a way to track your data usage (in addition to the meter on your phone), but you can set apps to run over wi-fi only. Part of the problem may be that your phone is always looking for a connection.
If you didn't do a system cache clear after the ICS update, it may help; it shouldn't erase any of your data:
Power down phone
Hold volume up/down & power simultaneously
Use volume down to navigate to 'Recovery', use volume up to select
Should see screen with triangle and exclamation point next to an Android
Press volume up/down simultaneously
Use volume rocker to navigate to 'wipe cache' and use power button to select
Once finished, use volume rocker to navigate to 'reboot system now' and use power button to select