What causes battery health to drop on iPhone 15 Pro Max?

atefeh98 wrote:

I have gone through 353 charge cycles with my phone.

For a phone to have 353 charge cycles, I would expect your battery health to be in the 92% - 93% range, so the battery health loss is a bit higher than expected. But it's not excessive. If you would feel better, schedule an appointment at your Apple Store Genius Bar and let Apple see your phone.

Genius Bar Reservation and Apple Support Options - Apple

Do you let your phones charge completely run down? It's not good for a Lion battery to become fully depleted and that can contribute to reduced battery health.

What most of us who have been on the forum for years do ourselves, is plug our phones in to charge when we go to bed at night, leaving them plugged all night EVERY night with Optimized Battery Charging turned on. We awaken to a fully charged phone every morning and usually have enough charge to get through the day. But if the battery gets down to 20%, it should be plugged in to charge to keep it above 20%.

How many charge cycles has your phone been through? Settings > Battery > Battery Health > Charge Cycles

You can expect about a 1% drop for every up to 50 charge cycles.

• How many charge cycles have been reported?
• Review the apps that are causing your battery to drain. This is done by going to Settings > Battery, and scroll down to view the app usage over the last 24 hours. Meta apps have been seen to make extensive use of background processes that continue to use the battery even when the app is not opened. Meta has acknowledged that they have updated their app to resolve the problem or bug, but an improvement has not been seen by all.
• Are you starting your day with your battery at a 100% charge. Many will limit the charge to 80% thinking that they are going to get much more life out of their battery, but in reality any benefit is likely minimal as there has been no documented information provided for what a user could expect, and you have the drawback of never having a device that is fully charged for use.
• Did you purchase the device new or was it used or possibly refurbished?

atefeh98 wrote:

I purchased my iPhone in June 2024, which means I’ve had it for about 10 months now. From the very beginning, I noticed that the battery would drain quite quickly, requiring me to charge it almost twice a day. Since the battery health was not initially low, I assumed this was normal.

However, over the past month, the battery health has unexpectedly dropped from 95% to 87%, which seems unreasonable given the short time span. At this point, I need to charge my phone up to three times a day, which is quite inconvenient. what should I do now?

[Re-Titled by Moderator]

It could be caused by frequent charging, but also consider if you are exposing your phone to extreme temperatures (this can be hot or cold) an excessive amount of heat or cold can wear your battery over time.If you eventually find yourself unable to use your phone and need to buy a new one, as of now you can get up to $630 trade in value for your phone.You can also probably get more selling 3rd party (eBay, swapa,etc)