iPhone XS went from 84% battery health to 75% in a week.

[gdourado]

Hello, hope everyone is doing well.
My wife is the least tech person in the world. Finally I got her to upgrade and got her a nice iPhone XS 256gb.
I got the phone used. Tested everything and everything was working great.
When I got the phone, the battery health was at 84%. Not great, but still usable for some time before absolutely needing a replacement battery.
The thing is that my wife has had the phone for under a week and in that time, the battery health as dropped to 75% currently and I think it might drop further.
First it went from 84 to 81 like overnight. Then to 78. Now is at 75...
I never saw such a steep drop in battery health before...
What might be the issue here?
Was I ripped off when I got the phone?

Thanks for your input.
Best regards.

 

[BugeyeSTI]

Battery needs replacement. If the phone was sold "as is" and you were aware the battery was at 85% then I don't think you can say you were ripped off. If the seller said the battery was in excellent condition then you might want to contact them and complain. 85% is a battery that has 5% of life left if that. My X stated to show the service battery soon notification and acted wonky at 82%.

 

[Fred Zed]

Time to go to apple and pay for a battery replacement.

 

[GMShadow]

Unfortunately batteries are finicky, and if they sit for a while they can often report fine and then fail once they start cycling again. Not ripped off, just bad luck.