Hello @sachins,
Welcome to Apple Support Communities!
We want to help you get the most from your iPhone battery and determine what it causing the drain.
Use the steps here to check your battery usage:
"Check battery usage
To see an overview of your battery level and activity for the last 24 hours and up to the last 10 days, go to Settings > Battery.
When you tap one of the time periods above the Activity graph (Last 24 Hours or Last [X] Days), you can see which apps contributed to your battery usage during that time period, and the proportion of battery used for the app.
To see how long each app was in use on screen (the dark blue bars) or in the background (the light blue bars), tap Show Activity. Under each app, you might see these usage types:
- Background Activity means that most of the app's battery usage — such as playing music or tracking location — happened while the app was in the background.
- No Cell Coverage and Low Signal means that your device was searching for a signal or being used with a low signal.
- Connected to Charger means the app was used only when your device was charging.
You can also see when your device was last connected to a charger and the last charge level. With iOS 16, you can see if charging paused because of Optimized Battery Charging, Clean Energy Charging, or temperature."
This Apple Support page has the full details: About the battery usage on your iPhone, iPad, and iPod touch - Apple Support
This can help you further isolate and resolve what is causing the battery drain by looking at the battery usage.
Cheers!