is there something wrong with my iPhone's battery?

[wlow3]

This has happened at least twice so far.

While updating a bunch of apps, my iPhone 6s (iOS 9.3.4) will suddenly shut down as if the battery is drained. If I try to restart it, it will shutdown again after a few seconds. Occasionally I'll see the image of the empty battery in the center of the screen while I'm trying to restart it, yet my battery indicator in the upper corner will read, say 34% (when I do get it restarted for a brief moment). Only plugging in the iPhone stops the repeated shutting down. And again, when I plug it in, the upper corner battery indicator indicates I still have plenty of battery power. Any idea what causes this? Thanks.

 

[lordofthereef]

Sounds like it could be a bad battery. If you have an Apple store nearby they'll diagnose for free.

 

[44267547]

The only thing I can think of is if your battery is lower than what the actual reading is on display, which can happen from Time to time. Especially when updating software and Applications, I would suggest your battery level be somewhere around 75%. Or if your battery is critically low and your updating, make sure it's connected to the charger.

 

[mtneer]

Since this is a 6s, it should still be in warranty (at least for another month). If your situation is reproducible, I would just take it to an Apple store and have them swap out your phone under manufacturer warranty.

 

[wlow3]

This has happened at least twice so far.

While updating a bunch of apps, my iPhone 6s (iOS 9.3.4) will suddenly shut down as if the battery is drained. If I try to restart it, it will shutdown again after a few seconds. Occasionally I'll see the image of the empty battery in the center of the screen while I'm trying to restart it, yet my battery indicator in the upper corner will read, say 34% (when I do get it restarted for a brief moment). Only plugging in the iPhone stops the repeated shutting down. And again, when I plug it in, the upper corner battery indicator indicates I still have plenty of battery power. Any idea what causes this? Thanks.

Ah ha. My phone has unexpectedly shut down when it was less than 60% full and doing something process(and battery) intensive, like updating all apps or recording video.

"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."

https://www.apple.com/support/iphone6s-unexpectedshutdown/