[Galaxy Note GT-N7000 Q&A, Help & Troubleshooting] AndroidSlave:
Remember: there is no app, that behaves in same way on different system. While it can drain on CM, it can be rock solid on the TW, and vice-versa. So, don't take those examples too serious and don't run to uninstall your apps just for preventive maintenance. Act per need.

So, as listed above, our Top Chart leader is Media Scan:

- Media Scan – process, that will run after each fresh install & reboot. Typically takes about 10-15 minutes, runs on high CPU frequency. If stuck more than this, causes no Deep Sleep (can be seen in CPU Spy app) – you have an issue with Media Scan. It can stuck on large files directory – nothing to do here, unless you can reduce files number. Another case – problematic memory cluster, and there is only solution to back up your data, format your storages, and start over.

Stopping the process won't help much, as on next reboot it will resume. Suggestion - charge the battery to 100% before Media Scan starts to rebel, and let it finish.

Another case - stopping any download (browser, market) in the middle. Media scan can possibly stuck until next reboot.

- Media Scan stuck:

1. You probably have some corrupted files, on which it stuck. Backup, start to restore to the step it was OK, to find the culprit

2. Folder with many files - likely to stuck or to spend a lots of time to scan it. Do the math. If you

have

to have this folder (likely to be a cache folder) - disable your media scan.

3. I/O scheduler - CFQ sometimes being reported as taking longer time to media scan to complete. Try NOOP.

4.And, of course, sometimes it won't work without formatting emmc and starting over.

- Google apps/services:

(in edit)

- Google Plus - there were cases, when this app, with auto-sync left, was just hanging in the memory and caused drain.

- Google Currents - depends on system, but there were also cases, when the service left active on CPU resource after it was even completely killed in task manager.

- Google Location service - if you choose to update your location by GPS only, expect wakelock, when GPS can't lock on a stellite. Second case - if location being updated from internet, and your mobile data is in bad state (poor signal, etc.). And, of course, it depends on apps, who require location update, and there are a lot of such. Whenever you don't need it - disable your locations service in Settings.

- Google Maps - brightest example of wakelock, caused by requiring your location. If you want to run Google Maps, disable the Location services, and disable Maps in start-up.

- "The Holy Trinity" - Skype, Facebook, WhatsApp. Just be sure to kill the app and & services, when you don't need it.

- Same applies for a clients of a kind: Viber, Twitter, etc.

- “Energy savers” – Green Power, Timeriffic, etc. They mess with the system power policy, if you choose to enable/disable wi-fi, gps, data, Bluetooth, etc. Especially, Samsung’s one (power policy) is known as problematic.

- “Soft-buttons”, so called “power button savers” – like ScreenOff & Lock and such. Related to previous group. Let the hardware do the job.

- Task killers - If it kills some services in the middle of their action, it will cause’em start all over again or even stuck, and eat your precious battery resources. If you have to use it (like in case with JB 4.1 memory leak issue, do it manually).

-Sopcast - very likely to stuck in memory, and to cause multi_pdp wakelock. Worse, it may keep consuming your precious data. Suggestion: reboot right after you ended using Sopcast.

- *new* - Weak network signal. Pretty understable, but still - weak network signal can cause some weird wakelocks. Especially, when you're on autosync on with mobile data, and the signal is weak, you will get "*sync*com.google.android.apps...." wakleock, "genie.widget" is you're syncing "new&weather" thing, RILJ is very likely, etc.