Why is my battery draining so much on standby?

[iMore Question]

Last night I went to bed with 29% battery remaining and left it unplugged all night. With my iPhone 6 I would wake up with around 20% remaining in this situation however this morning after seven hours of sleep I woke up with only 11% remaining. Then after using the phone for about 30 seconds it completely turned off and was dead. In the settings I looked at what was draining the battery the most and 41% (which was by far the highest percentage) was allocated to Siri. I've never used Siri since I bought the phone last week and I have the "Hey Siri" function turned off. Does anyone know what this Siri drainage could be from?

 

[erichards2]

Not sure about the Siri function, but I would guess this could be a battery issue itself. It's reported that after 13 months, a new iPhone only holds 80% of it's original battery. If older, I'd assume this gets even worse. I'd recommend getting a battery case such as a mophie case.

 

[G.4]

This is likely due to what can be called a "rogue process" in the background associated with Siri. Try rebooting your phone to see if it goes away first. Sometimes things just get "hung up" and run and run in the background without your even using the function. Just like a regular sized computer, your iPhone needs to be rebooted from time to time.

 

[Adramyttium]

The recommendation to reboot is solid. I help managed 1,400 iOS devices for a local schools district. While iOS is excellent, I recommend to students that they regularly perform a "hard reset" of the device. Hold the power button and home buttons together until the device shuts off and the apple logo appears. If the problem still occurs after you do this, you probably have an app that's causing problems.

 

[xderiwx]

I have a 6S Plus, but I have been noticing that Background App Refresh has been turning itself on for every app, even though I have it on for only two since the iOS 10 upgrade. Maybe check on those settings along with the other suggestions?