Apple has admitted to getting something a bit wrong. It says that a batch of batteries put into iPhone 6S units between September and October 2015 are a bit on the rubbish side, and is offering to have them swapped out free of charge should you have one of the rogue models.
It's part of an effort to fix the "unexpected shutdown" issue that some owners have been moaning about, with Apple saying of the problem: "... a very small number of iPhone 6S devices may unexpectedly shut down," which, in Apple terms, is quite the massive apology.
Any old Apple Store ought to be able to handle the repairs by checking to see if the serial number of the phone matches the database of affected devices, and users who've already paid for a repair or replacement to their iPhone 6 out of their own money are able to claim a refund too. [Apple via USwitch]