iPhone 15 Pro Max Battery Health Dropped to 99% at 27 Cycles

How long have you owned your iPhone? On average, it's pretty common to see a loss in battery health of about 1% per month. Typically, we see battery health decline 1% for UP TO 50 charge cycles, but that is under ideal conditions and no one actually knows what ideal conditions are. The health of your battery could actually be 99.8% as opposed to 100%, yet it will be displayed as 99%. If you've owned your phone a few months, which you likely have, I wouldn't be in the least concerned with a 1% decline in battery health. And you will continue to lose health as that's what batteries do. When the day comes that the health of your battery declines to 80% or less, that's when it's time to pay Apple to replace the battery. Until then, worrying over the natural and unstoppable decline in battery health isn't worth the time or worry.

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

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

See the pic below (iPhone 12 Pro iOS 17.3.1)

"Show Activity" feature will show you more info see the pic below

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)
7. Disable Push Email: Push email notifications can drain your battery quickly. Instead, set your email accounts to fetch data manually or at longer intervals. You can change this setting in Settings > Mail > Accounts > Fetch New Data.

I noticed that my battery health has dropped from 100% to 99% at just 27 charge cycles.

Apple always rounds down any tenths of a percent in the battery numbers. So, your battery was at 100.0% and it declined very slightly to 99.9%.

That 99.9% will be displayed as 99%. So, it looks like the battery dropped 1% when it only dropped .1%.

You don't need to be checking the battery all the time. It will only make you nervous. At 250 Cycles, it will at or about 95%. At 500 Cycles, it will about 90%

The phone was manufactured in May 2024, and went into service in February 2025. That means the phone sat on a shelf for months without being charged, which is not good for Lion Batteries. Losing what you've lost makes total sense based on this. When Lion batteries aren't charged for an extended period of time, they lose battery health faster. There is nothing wrong with your phone. So worrying about the natural decline is pointless. Enjoy your phone and when its battery health dips to 80% or less, which it will if you own it long enough, pay Apple to replace the battery.

mahmud124 wrote:

So that means the remaining health will drain faster than other phones??

We can't predict that. My guess would be no. Whatever health it lost while sitting on a shelf for those several months is lost. But it doesn't necessarily mean it will lose health any faster now that it is being charged.

mahmud124 wrote:

So that means the remaining health will drain faster than other phones??

You are just looking at too small of a sample size to make any determination. On average, you will see a drop of about 1% for every 50 charge cycles, but what you are seeing now may simply be rounding of your actual Battery Health. For example it may actually be 99.49% that was rounded down to 99%. Once you get up to about 200 charge cycles, then you can expect the Battery Health to be showing about 96%, where rounding will have less of an impact.