How much battery health would a new in box iPhone 6s battery have?

[sagah]

Assuming that it was manufactured a long time ago around the time 6s came out, how much battery health might it have left? Would it being so old make the battery health around 90% Or could you expect it to have at least 95%?

Do they still make these batteries nowadays or would the batteries available now all made years ago?

(I'm trying to buy one from eBay)

 

[ian87w]

If it comes with a modern iOS with the battery health feature, I'm guessing it will simply show 100%, but then real life battery performance will degrade very very quickly, or worse, gets swollen or simply fail within a short time.

Do note that Apple did have a repair program for the 6s due to the battery, and they have stopped that since it's been a while, so you're gambling that you would get a unit that is affected by the repair program and you have no recourse at this point.

I wouldn't buy a 6s in any condition at this point. If you want a TouchID iPhone, just get the 2022 SE.

 

[sagah]

Problem is I already bought it, and the battery life is really bad.
I bought it because it was cheap used and had a 3.5 jack.

I wonder if there is a 3rd party battery solution where the battery weight won't be bigger than the OEM battery. I already paid the replacement fee, but the 3rd party battery they used weighed noticeably heavier than the OEM battery.

(When they measured the weight upon my request, it came out to be difference of .9 and 1.1 oz or .02 oz or 5.6 grams.)

They agreed to switch the battery to OEM battery if I buy it myself and bring it in.