Hi Malikbilalejaz
Welcome to the Apple Community.
Wondering if you might want to update to iOS 15.2
Re: "really worry about this issue"
It may be not worth the worrying ... What is the worst that can happen ?
Battery replacement ? ... maybe $0 .... or, if / when it becomes necessary up to $69 US
Details: https://support.apple.com/iphone/repair/service/battery-power
In the meantime:
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Re: Battery health
Apple support have articles online that may help.
About the battery and performance of iPhone 11 and later
https://support.apple.com/en-us/HT210557
iPhone Battery and Performance
https://support.apple.com/en-au/HT208387
Monitor the iPhone battery level:
https://support.apple.com/en-au/guide/iphone/iph4747a74a9/ios
Tips about maximizing battery life and lifespan:
https://www.apphttps://support.apple.com/en-us/HT210512
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Apple support also have articles about charging, that may be helpful..
About charging the battery
Eg: You can scroll to "Turn on Low Power Mode"
https://support.apple.com/en-au/guide/iphone/iph63eecc618/ios
More About Optimized Battery Charging on your iPhone
https://support.apple.com/en-us/HT210512
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You can always talk to someone at Apple about the battery issue,
and especially if you have Apple Care / or / device under Warranty.
Apple do want people to be happy with their products,
There is a "Get Support" link to Apple at top right on this discussion page.
Or
You might visit an Apple Store: a Genius Bar reservation is recommended:
How to make a Genius Bar reservation at your favourite Apple Store, and get help from an Apple expert.
Genius Bar Reservation and Apple Support Options - Apple
Or
From iOS device you can use the app to easily make an online Genius Bar appointment:
https://itunes.apple.com/us/app/apple-support/id1130498044?mt=8
Or
Apple phone numbers around the world
Contact Apple for support and service:
https://support.apple.com/en-us/HT201232
All the best :=)