The latest software update for the OnePlus One has significantly reduced the handset’s battery life for a large number of users. CyanogenMod, which is responsible for the One’s pre-installed software, says issues with the proximity sensor and power management are to blame, and it is already working to roll out a fix.

The One’s “XNPH30O” update was released over-the-air earlier this week, and it is the first major update the handset has seen since its release. In addition to a long list of welcome bug fixes, the software introduced the Clear Image camera feature. It also ruined the One’s otherwise excellent battery life.

More than 130 users have reported the problem via the CyanogenMod issue tracker, and there are countless threads about it on the OnePlus forums. “After installing the 30O OTA update, battery drain in standby significantly increased,” writes LesPaulAT. “Last night, 8 hours in “Airplane Mode”, it drained 8% of the battery.”

The good news is, CyanogenMod has already acknowledged the problem and (almost) fixed it. Issues with power management and the One’s proximity sensor are responsible for the abnormal battery drain, but while the former has been fixed, CM is struggling to replicate the proximity sensor issues.

CM’s Steve Kondik promises, however, than the team is “all over it,” and he promises an expedited over-the-air update will be made available to all CM11S users once the changes have been confirmed. It’s not completely clear at this point how long that will take, so you may want to carry a battery pack or at least a charger in the meantime.

And of course, if you haven’t already updated your OnePlus One, it’s probably best to avoid doing so until the new software is ready.

• SourceCyanogenMod
• ViaAndroid Police