An Apple logo hangs above the entrance to the Apple store on 5th Avenue in the Manhattan borough of New York City, July 21, 2015.

An Apple logo hangs above the entrance to the Apple store on 5th Avenue in the Manhattan borough of New York City, July 21, 2015. Reuters/Mike Segar

Apple has released an official statement regarding the iPhone 6S battery issues that have affected a number of users. The tech giant says that the unexpected iPhone shutdowns “can occur under normal conditions” and that the main culprit of the batteries’ problems is “ambient air.”

After launching an iPhone 6s battery replacement program about two weeks ago, Apple says it is done investigating the issue. The Cupertino-based company points to “controlled ambient air” as the reason why select models of the iPhone 6s have been shutting down unexpectedly.

READ: Apple iPhone 'Game of the Year' now available on Apple TV

“As a result of our investigation on this, we found that a small number of iPhone 6s devices made in September and October 2015 contained a battery component that was exposed to controlled ambient air longer than it should have been before being assembled into battery packs,” Apple explained in its post.

The iPhone maker apologised for any inconvenience the battery mishap may have caused but reiterated that it’s not a safety issue. Apple also acknowledged the handful of iPhone 6s users who have experienced untimely shutdowns despite owning handsets that fall outside of the supposedly affected models. The company seemed to downplay the shutdowns as common manifestations.

READ: Apple iPhone 8 update: New 4.7-inch iPhone 8 could be the iPhone SE's successor

“A small number of customers outside of the affected range have also reported an unexpected shutdown. Some of these shutdowns can occur under normal conditions in order for the iPhone to protect its electronics,” Apple clarified.

To help figure things out, Apple is going to include “additional diagnostic capability” in its new iOS software update that will be made available next week. The diagnostic tool will allow Apple to gather enough information for it to improve its capacity to manage battery performance and inconvenient shutdowns. Apple added that any progress and fixes developed out of the data that will be collected shall be delivered in future software updates.