In the X5iii the real battery consumer is the hardware itself. FiiO says that "Because of the chip limitation, our X5III may have bigger stanby current than some phones".
In "standby mode" has a sustained consumption of approximately 10/12% every 8 hours. Nothing to do with that.
Apart from that, everything related to Google Services always consumes many resources and as Google updates versions is consuming more and more.
If you really want to "free" resources on the X5iii there are many things that can be disabled, but others are blocked and you can not.
Once I installed the apps I wanted (Spotify basically), I have disabled/unistalled all that:
- Android Live Wallpapers
- Android System WebView
- Basic Daydreams
- Black Hole
- Bubbles
- Clock
- Com.android.smspush
- Com.android.wallpaper.holospiral
- Exchange Services
- ES Explorer
- HTML Viewer
- Music Visualization Wallpapers
- MusicFX
- One Time Init
- OpenWnn
- Phase Beam
- Photo Screensaver
- And something a chinesse ...
In a second round, i remove (disable) all Google related services. Obviously, you lose the app store, but I actually install apps directly as apk, and of course you lose the link to the google account.
- Google Account Manager
- Google Play services
- Google Play Store
- Google Services Framework
Another thing you can do is uninstall ES Explorer (which is rubbish) and install a good and light browser like MiXplorer
http://www.apkmirror.com/apk/hootanparsa/mixplorer-hootanparsa/mixplorer-hootanparsa-6-13-1-beta-release/mixplorer-6-13-1-beta-android-apk-download/
The system is now as clean and fluid as it can be with the original ROM and everything I use works fine. In any case you can always re-enable everything