If you havnt already done so, download the latest NPS and update to the latest firmware. Anything above G8 will show significant battery improvements. The latest is I5
(A= january, B = Feburary, etc, and the number = build number. So I5 = September build 5)
The latest NPS will now sync and everything else too
There is a known problem that the case depresses the camera button which stops the phone from going into full sleep. Try the phone without the case for a day (or pull it out of the case and put it on your desk whenever possible) and notice the massive difference! Just try it out of the case overnight, to see you'll have a 0% battery drop overnight!
Just these two changes will improve battery from 1 day to 2.5 days - including medium usage.
Other things you can do..
- Turn off google autosync - who needs it, unless you need instant gmail
- Turn off background data - most widgets don't need it, and if you're not auto syncing its not really necesary
- Use 2G mode and toggle to 3G if you need to use the web. The I5 build has a new switcher app - similar to the free ones you get on market to toggle wifi etc.