The free upgrade likely relates to the company's current shortage of iPhone 6 Plus battery replacements. If you have an iPhone 6 Plus with defective hardware such as a faulty Lightning connector ...

If you buy through a BGR link, we may earn an affiliate commission, helping support our expert product labs. If you own a relatively old iPhone 6 or 6 Plus model, you can restore it to former ...

I did exactly that, replacing the old battery of a well-used iPhone 6 to give it a new lease on life. I was pleased to find the phone on eBay for only £75 (about $100 or AU$140) back in 2020.