Cyanogen OS 12S
Wakelock issue with Cyanogen OS 12 (CM12) causing rapid battery drain, patch coming soonCyanogen

Several Cyanogen OS 12 (CM12S) users have been reportedly complaining about reduced battery life with the new Lollipop Cyanogen update as the device never goes to deep sleep, owing to the inherent wakelock issue with Google Play Services.

According to Android Police, the root cause of the bug has been attributed to the OTA update component of Google Play Services (SystemUpdateService), which was disabled in KitKat and earlier versions of Cyanogen.

Wakelock issue in Cyanogen OS 12
Wakelock issue with Cyanogen OS 12 (CM12) causing rapid battery drain: How to fixAndroid Police

It is ascertained that just disabling Google's OTA update service will not work with Android 5.0 ROMs as the update service acquires a wakelock to check for updates and since SystemUpdate Service is disabled in Lollipop, the update check will never complete and the device stays awake.

As the device has been hardcoded to behave in a certain way with Play Services 7.x onwards, there is no way to bypass this mechanism. Hence, the wakelock issue has been credited as the primary source of the rapid battery drain problem on all Android devices running the latest Cyanogen firmware.

Cyanogen OS 12
Wakelock issue with Cyanogen OS 12 (CM12) causing rapid battery drain: How to fixAndroid Police

On the brighter side, Cyanogen OS users can feel relieved knowing that there will be a quick-fix coming out by next week to alleviate the problem, wherein the fix involves re-enabling SystemUpdateService and locking down other apps or services linked to it.

Currently, there is no working patch for this issue with third-party custom ROM developers. However, a modded Play Services package (download here) from XDA Developers should help in fixing the wakelocks problem at least temporarily, until a permanent fix is released.

Here is how you fix the wakelock issue:

  • Download the modded Play Services package from the above link
  • Flash the zip file via stock recovery