In early January, Senator John Thune (R-S.D.), chairman of the Commerce, Science, and Transportation Committee, called upon Apple to answer for the lack of transparency it showed surrounding its slow-down practices for aging iPhones. Today, Thune's office released Apple's response: a five-page letter in which Apple reiterates the slow-down saga. While the letter contains little new information, Apple does touch upon how it may handle customers who already paid full price for battery replacements. The company also hinted at how newer iPhone models will deal with aging battery issues, but Apple did so in a way that doesn't instill confidence that it will, in fact, be more transparent with its practices in the future.

In the letter dated February 2, 2018, Apple explains how the lithium-ion batteries found in its iPhones age over time and become less able to handle high workloads. To avoid unexpected shutdowns caused by these aging batteries, Apple issued a software update that we now know included a feature that deliberately slowed down the performance of older iPhones to prevent such shutdowns.

Apple addressed transparency only by noting that its updated iOS 10.2.1 ReadMe notes included mention of the power management feature and that it issued a statement to press outlets about seeing "positive results" from the software update.

Otherwise, the letter is a slightly more detailed description of the timeline of events leading up to, during, and after the battery controversy. Apple explained the same situations for customers in its official apology on its website, which also announced the company's new battery replacement program. Apple lowered the price of out-of-warranty battery replacements from $79 to $29 and promised new UI features that would give customers more insight into their phone's battery health.

In January, Apple announced it would allow users to use a new UI tool to turn off the power management feature that slows down old iPhones. While Apple doesn't suggest turning the feature off, customers will be able to do so if they wish.

Nuggets of new information, plus more questions

The Apple letter contains two pieces of information that prompt more questions rather than shed any light on the situation. First, Apple writes that it is "exploring" options for customers who paid full price for battery replacements before the new program was put in place. There have been rumors about Apple offering partial refunds to these customers, but nothing concrete has been announced yet. Apple states it will update the senate committee at some point in the future when it decides how to handle these cases.

Second, and more peculiar, is part of Apple's response to being asked how it will specifically handle the throttling of newer iPhone models:

iPhone 8, iPhone 8 Plus, and iPhone X models include hardware updates that allow a more advanced performance management system that more precisely allows iOS to anticipate and avoid an unexpected shutdown.

That means the newest iPhone models have some sort of improved hardware that allows the handsets to better handle peak performance workloads and avoid sudden shutdowns—but Apple hasn't detailed what these hardware improvements are. The statement also raises questions about whether the existing power management system will also be deployed in iPhone 8, 8 Plus, and X models when they're considered "old" (if at all) or if the hardware improvements are enough to withstand the effects of aging batteries on iPhone performance. Currently, iPhone 6, 6 Plus, 6S, 6S Plus, 7, and 7 Plus models are equipped with the slow-down feature.

So while most questions about the recent battery controversy have been answered as thoroughly as Apple will allow, there are now new questions about how newer iPhone models handle similar situations going forward. It appears the newer models will indeed handle aging batteries and peak workloads better than their predecessors, thanks to special hardware, but exactly how is unclear.

Thune's original inquiry questioned Apple's transparency regarding its slow-down practices, suggesting the company should have been more transparent with its customers about under-the-hood features that affect their iPhones. Transparency was the core issue for many outraged customers as well—while Apple may have been right to slow down iPhone performance to prevent user-facing problems, the vague disclosure of its methods made many users question their trust in the tech giant.

Apple's statement about the iPhone 8, 8 Plus, and X hardware is just as vague as its original disclosure of the slow-down practices. It will likely cause customers to continue to question how much they can trust Apple to be transparent about new hardware and software features.

Senator Thune issued a statement about Apple's response letter: