In recent news, Apple announced in a document that a problem is indeed plaguing the iPhone 6s and 6s Plus. According to the acknowledgement note, it describes that the iPhone 6s and 6s Plus battery percentage isn’t reflecting the actual power draining.
In addition, Apple also gave instructions on how to fix this problem. Before jumping into how to fix the drained battery display issue, Apple explains that it’s caused by users manually changing the time or when they pass through different time zones.
To help fix this problem, simply reboot your iPhone and make sure that the date and time are set automatically by going into the General menu in iOS 9’s Settings app. However, if the problem still occurs after the current solution, you should contact Apple’s support staff. With that said, you can read the aforesaid in Apple’s support note below…
“If you change the time on your iPhone 6s or iPhone 6s Plus manually or change time zones when traveling, you might notice that the battery percentage doesn’t update.”
As of now, the problem has been noted to be plaguing users ever since last September. The company noted that they will soon bring a fix to this problem, whether the time was changed manually or if different time zones were crossed.
Source info: support.apple.com