iPhone 18 Pro Max Battery draining in 2 hours

Are you charging your phone all night, every night while it is connected to WiFi? The background indexing responsible for the battery draining, heat, and some UI lag after any update continues for about 5-7 days. This may take longer if not being connected to power and wifi to let those complete quicker.

I would recommend posting the Screenshot at Settings > Battery > View All Battery Usage that includes both battery graphs and the top 5 apps consuming your battery. If you see high usage for System processes at the bottom on the screen, then post that as well.

Thank you everyone. After 10 days of my battery draining, and the iphone running hot (didn't mention that before) and my watch exhibiting the same behavior, after upgrading to iOS 27, I turned off Optimized Battery Charging, Clean Energy Charging, and left Adaptive Power on, and upgraded to iOS 27.2. The iPhone 18 Pro Max is now running cool, and not draining, same with my watch, and did not change the apps or usage. It was probably the upgrade that did it, but I haven't turned the battery settings back on to test.

The measure of battery health deterioration/drainage is subjective and can vary depending on individual usage patterns. There is no universal standard to determine whether the battery health deterioration/drainage is normal or abnormal because it heavily relies on how the battery is used and maintained.

Protect & Prolong the Life of your iPhone's Battery:

1. About the battery usage on your iPhone, iPad, and iPod touch ...
2. Batteries - Maximising Performance - Apple (IN)
3. iPhone Battery and Performance
4. About Charge Limit and Optimised Battery Charging on iPhone - Apple Support (IN)

• Find out what to do if Optimised Battery Charging doesn’t activate.
• Find out what to do if your device stops charging unexpectedly.
• Find out what to do if you think your battery is draining too quickly.
• Find out how to charge and maintain your iPhone battery.

Try to monitor Battery usage by iPhone Activity as shown below

What is shown under battery usage? Checking that would give you an indication of the usage behavior.

1. Background Activity
2. Notifications
3. Connected to Charger
4. Or any Other

Try some of these options too.

To prolong the life of your iPhone battery, you can follow these tips and best practices:

To prolong the life of your iPhone battery, you can follow these tips and best practices:

1. Optimize Battery Charging: Enable the "Optimized Battery Charging" feature on your iPhone. It helps reduce the wear on the battery by slowing down the battery aging process. You can find this option in Settings > Battery > Battery Health. About Optimized Battery Charging on your iPhone - Apple Support (IN)
2. Avoid Extreme Temperatures: Extreme temperatures, both hot and cold, can negatively impact your battery life. Avoid exposing your iPhone to excessive heat or cold, such as leaving it in direct sunlight or in a freezing car.If your iPhone or iPad gets too hot or too cold – Apple Support (UK)
3. Use Original Chargers and Cables: Always use Apple's original chargers and cables or certified third-party accessories. Low-quality chargers or cables can damage the battery and reduce its lifespan. Identify counterfeit or uncertified Lightning connector accessories - Apple Support (IN)
4. Avoid Draining the Battery to Zero: Charge it whenever the charge becomes lower than 20%. The rest is up to you when to charge. how long to charge, how often to charge, which adapter to use starting from 5W to 140W USB-C Power Adapter etc.
5. Optimize Display Settings: Adjust your display settings to optimize battery life. Lower the screen brightness, enable auto-brightness, and use shorter screen timeout durations. Adjust the display and text size on iPhone - Apple Support (IN)
6. Minimize Background App Refresh: Limit the number of apps allowed to refresh in the background. Go to Settings > General > Background App Refresh and disable it for apps that don't require real-time updates. Switch apps on your iPhone, iPad, or iPod touch - Apple Support (IN)

How to check your iPhone battery for Self… - Apple Community

DANAKM24 wrote:

Thank you everyone. After 10 days of my battery draining, and the iphone running hot (didn't mention that before) and my watch exhibiting the same behavior, after upgrading to iOS 27, I turned off Optimized Battery Charging, Clean Energy Charging, and left Adaptive Power on, and upgraded to iOS 27.2. The iPhone 18 Pro Max is now running cool, and not draining, same with my watch, and did not change the apps or usage. It was probably the upgrade that did it, but I haven't turned the battery settings back on to test.

At time of writing ios27.2 is only available to beta testers and this place does not allow discussion, but thanks for the feedback anyway.