An error in the operating system makes phone use CyanogenMod significantly more battery than usual.
If you have just gotten OnePlus update XNPH30O, so you might have discovered that the phone does not hold a charge as long as it used to do, in this case, you are certainly not the only one.
Cyanogenmod has a thread on their forum with over 100 comments on the subject, and it seems that they have identified the problem. There seems to be a problem both with proximity sensor and the module that manages power consumption.
On the positive side is that supposedly by being in control of both problems and CyanogenMod will therefore hurry to push an update out, exactly when it ends up to be on our OnePlus phones is not known immediately.
The increased power consumption is enough to it can be felt in everyday use, but not quite enough to phone neither gets hot or outright unusable. No matter what we are waiting in suspense for an update so that the battery consumption can get down at the original level.