User level: Level 1 (4 points)iPhone 18 Pro Max is heating up/ cools down… doesn’t hold a charge. Done everything app refresh, checked unused apps, turned phone off and on… took out case… still heats up / cools down. Can’t be on any app long. Why? Should I return this phone?
Posted on Oct 17, 2026 9:38 AM
User level: Level 10 (244,490 points)Oct 17, 2026 9:50 AM in response to MsMikko
It is normal for any smartphone to run warm when it is in use, as explained by the 2nd law of thermodynamics. What do you mean by “doesn’t hold a charge?"
If you charge the phone overnight with Optimized Charging enabled (a Best Practice) it should not require charging during the day, until the next overnight charging. If it meets this standard then the iPhone is working as designed.
Battery drain is directly tied to how you are using your iPhone, including cellular voice and data usage, apps you use, screen brightness, how often you use the iPhone, age of the battery and many other factors, most of them under your control.
In a new iPhone or after an iOS update the battery will drain faster for a couple of days while iOS builds its databases, such at the search database. Thus, it is best to leave it plugged in more than usual in those days.
Here’s a more detailed answer from Apple Support: If the battery in your iPhone drains too quickly - Apple Support
Originally posted at discussions.apple.com/thread/256377918