sydoto Said:
"My iPhone battery was replaced a few weeks ago and is at 100% max capacity. The battery drained at a very slow pace until a couple days ago where it started draining quicker. I also use the speaker close to the maximum volume."
-------
So, who replaced the battery? If make be faulty. Or it may be ungenuine.
Refer to the following when getting anew battery...
Finding the Price of a New Battery:
Looking for an iPhone Battery?
Get one from one of the following three locations. Getting it elsewhere, you might end up getting an non-genuine battery. Learn more here: About Genuine iPhone Natteries - Apple Support
A. Contact Apple Support:
If purchased from Apple, or covered under AppleCare, then get this serviced by Apple.
- Contact Us - Choose Locations
- Proceed from there as necessary
- Note: Phone calls are taking a bit to go through at the moment, due to lots of calls. And that makes sense because with the Coronavirus Pandemic, many are at home at the moment, with much time on their hands to contact Apple. So, just stay on the line, and you will get through :)
Or..
B. Contact an AASP:
Also, take this to an AASP (Apple Authorized Service provider), asking for assistance.
- Go Here: Find Locations - Apple Authorized Reseller
- Click: Service & Support
- Enter: your location information
- See: if there is an AASP nearby
- Contact: an AASP that shows up, and find out more about the services that they offer to fix the iPhone
Or...
C. Contact A Retailer:
Contact your local retailer, seeing if they replace these.