Hello Edwardntx,
The first thing you have to know is that if your battery Health is 80% or less you should to replace it!
Troubleshooting iPhone Battery Draining:
Refer to the Following:
I. Upgrade Once More:
Upgrade to the latest update.
Go Here: Update your iPhone Using a Computer - User Tip
II. Report this to Apple:
Do your part: Let Apple know what is going on here. Provide them with feedback on this. They may not get back to you directly, but the more feedback they received on this, the more they will know what is going on, and what needs to be fixed in updates to come.
- Go Here: Feedback - iPhone - Apple
- Comment: on when the issue began, and how you have troubleshot it thus far.
- Select: "Bug Report" for the "Feedback Type"
- Proceed from there aw necessary
II. Troubleshooting iPhone Battery Draining:
Refer to the Following...
A. Battery Drain Info:
The iPhone battery will drain, unless it is plugged in and charging. With lots installed, the charge would be slower. As for how fast it would drain the battery, that would depend on the battery health and the volume (sound) you use.
- Go Here: iPhone Battery and Performance - Apple Support
- Scroll Down: to "Your battery's maximum capacity"
B.. Troubleshooting the Battery:
And look at this user tip:
• The last update killed my battery! - Apple Community
Leave your phone plugged in and charging overnight. Once the battery is charged the phone will switch to using power from the power supply. Once the power supply is removed the phone will switch to using battery power.
Do not make a habit of closing all apps. It takes more system resources to restart an app from scratch than it does for a suspended app to pick up where it left off.
Make sure optimized charging is turned on: Settings > Battery > Battery Health > Optimized Battery Charging
Your battery will chemically age over time, there is nothing you can do to avoid this.