If you’ve noticed that the camera app on your Nexus 5 has been draining your battery more than it should, we’d say you’re not alone. There is either a new bug or the previous bug is alive and well and draining you of your phone’s charge. An “mm-qcamera-daemon” activity has been showing up on some Nexus 5 phones. The issue reportedly appears when the daemon enters a stuck state, which then consumes a large number of CPU cycles and drains your battery faster. And while Google won’t publicly comment on this issue, they seem to be working on it. A Googler marked the bug as “future release in the AOSP tracker. This means there is a chance that Android L update will remedy this issue.
Source: Ubergizmo