Apple has determined that a very small number of iPhone 6s devices may unexpectedly shut down. This is not a safety issue and only affects devices within a limited serial number range that were manufactured between September and October 2015.
If you have experienced this issue, please visit an Apple Retail Store or an Apple Authorized Service Provider and have your device’s serial number checked to confirm eligibility for a battery replacement, free of charge.
Check it here
Here is an interesting finding observed by some Surface Pro 4 users. According to them their devices Surface Pro 4 are experiencing unusual battery drain when the devices are being put to sleep or standby.
Here is the observation:
It clearly shows Hello is responsible for this.
So what’s the workaround?
Until Microsoft comes out with a permanent fix you can try to disable Windows Hello. To do this:
Settings > Accounts > Sign-in options >remove facial Windows Hello login.
There are negative feedback from a few users -they are experiencing significant battery drain on their Surface Pro 2 since the April 2014 updates.
A user reported that 25% CPU usage at all times even after everything was fully indexed.
Check it here.
According to a problem of a user -Microsoft UART V2 Driver (\_SB.UAR3) seemed to be the greatest consumer of battery when he came to conclusion using Powercfg /sleepstudy command.
And the workaround suggested by Arvind M. [MS]:-
“turn it on as a workaround. Swipe in from right to bring in charms bar, tap on Settings and then on Change PC Settings at the bottom. Subsequent steps to get to the switch to enable Bluetooth:
Change PC Settings
PC and Devices
“Powercfg /sleepstudy reports any issues that are preventing the CPU from entering its lowest power state during Connected Standy (e.g. screen is off). In this case, the state of the specific UART controller is preventing the CPU entering its lowest power state. This UART happens to be connected to the Bluetooth radio on Surface. Unfortunately, the bug that causes this bad state occurs exactly when the Bluetooth radio is turned off in PC Settings.
It is reasonable to want to turn off the Bluetooth radio to conserve even more power, but be aware that the major contributor to drain on battery is overall system power use, not just an individual radio.
Microsoft teams are aware of this issue in the preview build of Windows 8.1.”