I was experiencing severe battery drainage also with Cyanogenmod on my old Google Nexus 3. Turns out the culprit was Google services keeping the location servic

I was experiencing severe battery drainage also with Cyanogenmod on my old Google Nexus 3. Turns out the culprit was Google services keeping the location service going to sleep. Turned out a newer update of Google Services just does something wrong on unofficial builds. You can see from the preferences which application is keepign the phone awake, but I think you might have to enable the developer options. Solution was hacky, had to install a runtime script which was called on each boot, so that the particular service was blocked. Or maybe it was just looking at the battery stats, not sure anymore.