The five-page letter, dated February 2nd and sent to Engadget this morning, pretty much rehashes the same information that Apple's been talking about since this whole thing went down, including Apple's timeline for dealing with the problem and the way lithium-ion batteries degrade over time. What's new, however, is the company's response to Thune's final question about whether customers who've paid full price for battery replacements will recieve a rebate to cover the cost above and beyond the new $29 replacement fee. "Yes, we are exploring this and will update you accordingly," wrote Apple VP for public policy Cynthia Hogan.

"For advanced technologies like an iPhone, consumers rely on clear and transparent disclosures from manufacturers to understand why their device may experience performance changes," Thune wrote in a statement to Engadget. "I appreciate Apple's response to my inquiry and the company's ongoing discussions with the committee. In those conversations, Apple has acknowledged that its initial disclosures came up short. Apple has also promised the committee some follow-up information, including an answer about additional steps it may take to address customers who purchased a new battery at full price."