Battery draining issue on iPhone 15 Pro Max

Take Facebook for instance and look at the Privacy Page in the App Store to see the information they gather about you. It requires battery power to get this information to their servers.

• Contact Info
• Health & Fitness
• Purchases
• Financial Information
• Location
• Contacts
• User Content
• Search History
• Sensitive Info
• Usage Data

if you don't use your iphone it will still be using power on incoming notifications, and cellular data traffic and GPS and wifi and Bluetooth and...

even if you fully turn the device off then batteries are still analogue chemical devices that will decay over time even if no electricity is being drawn

have

you read

About

the battery and performance of iPhone 11 and later - Apple Support

and

maybe

iPhone

Battery and Performance - Apple Support

and

Batteries

- Maximizing Performance - Apple

As I predicted in my previous post, you have Meta consuming your battery with their Facebook and Messenger apps. It makes no difference if you are using the app or not as they drain your battery in the background. They design their apps to do just that and their servers are communication with the app on your device to update your Social Media graph. That is the information that Meta uses to sell to advertisers. All Apple does is tell you what is consuming your battery, how you respond is up to you.

• Remove those apps and your battery will lost much longer.
• Complain to Meta. They are not likely to change anything because they make billions selling your information to advertisers and you are not paying them anything.
• Live with the battery draining knowing what is causing it.

The choice is yours to make.

Your Battery Health is perfectly fine after 65 charge cycles and is correctly showing a 98% Battery Health.

For your Battery draining when not using the phone, that is due to Background Processes from app(s) you have installed. This is most notable for Meta apps as they are poorly developed and continue to harvest your information. That is their business model as the apps are free for you to use, but you are the product being sold to advertisers.

Post a screenshot of the Battery Usage by Apps for the last 24 hours by going to Settings > Battery, and scroll down to see the list of apps.