Battery in unused iPhone 8

As others mentioned….if it was never used how could the seller or you know the battery health? The settings menu wouldn’t be accessible to see that without having used the phone (set it up). Assuming the phone sitting for a long time without ever being used hasn’t caused any issues (including the likelihood you will need to replace the battery which isn’t a huge deal assuming you paid a great price for the phone) the phone is a decent one. Especially if you’re not concerned about its inability to update to current iOS and the user is likely going to be using it for very basic tasks being new to smartphones.

If the phone has been sitting unused for 3+ years, it may have suffered irreversible battery damage. As Johnathan asked, how do you really know what the battery health is?

Phone was discontinued 3 years ago.

If it’s unused, how do you know what the battery health is?

If you're not concerned about the shorter supported life of the phone, it's a good phone. And, you can still get the battery replaced at a reasonable cost if that's an issue.

The iPhone 8 was released by Apple 6½ years ago. It cannot use iOS 17 or greater. So the battery at 100% seems a secondary consideration. Apple considers products obsolete when they have come off the market more than seven years ago.

Ah, I understand. You’re getting a bargain price.

But be careful … see this article.

If you want to buy a preowned iPhone - Apple Support

Strollerman wrote:

This is not for my use - I have a 12Pro - but to be a transition device for someone who has not yet moved to a smartphone.

If I were recommending an iPhone for such a person, it would be the least expensive, least robust of the current model iPhones. At this time, that’s the iPhone SE.