I've had my Razr for quite some time and I've found a few tips to help make the battery last.
1. Turn off Facebook notifications.
This was a huge thing. Go to the Facebook app > settings > Notifications set to "off".
2. Don't leave WiFi or Bluetooth on when not in use.
3. Switch to 3g when 4g is not needed.
4. Turn off "in pocket detection".
With those 4 settings, my Razr lasts literally all day, even with heavy use.
1. Turn off Facebook notifications.
This was a huge thing. Go to the Facebook app > settings > Notifications set to "off".
2. Don't leave WiFi or Bluetooth on when not in use.
3. Switch to 3g when 4g is not needed.
4. Turn off "in pocket detection".
With those 4 settings, my Razr lasts literally all day, even with heavy use.