iPhone 5S - fast battery draining, heating

[iMore Question]

Hello,

I bought an used iPhone 5S 16 GB on German eBay. All works fine, but the battery is draining extremely fast and sometimes the phone, by my subjective view, a bit heats.
It came with an invoice that there was exchanged battery on 10th April 2018 (there was no IMEI on the paper).
In the auction there were 2 screens regarding the HW:
imgur.com/k5G5EAF
imgur.com/qc32n3B

I've applied a few saving battery from this article: lifewire.com/tips-to-extend-iphone-battery-life-1999884

Here is an info about the battery from iBackupBot (Windows version):
imgur.com/3Axjw0z

I was listening music from Youtube and the battery went down from 100% to 40% within 1,5-2 hours!

Could be there problem with defective U2 chip?

It was sold as fully working, should I start opening a dispute on eBay?

Thank you

 

[pkcable]

I would guess the battery itself is going. You can check, via Settings, then Battery, then Battery Health (Beta). Check the Maximum Capacity, and Peak Performance Capability. If Max Capacity is 50% or below then you should have Apple replace the battery. Peak Performance should say normal.

https://www.imore.com/iphoneslow

Apple Germany....

https://support.apple.com/de-de


EDIT: Oops just re-read your post, seems like Apple already replaced the battery. Please contact them and ask for a diagnostic. Often this can be done remotely, but if not they can schedule you an appointment with a Genius.