iPhone 13 battery health deterioration

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.

• Sounds like the 90% number this month is more accurate than the 96% number you would have had last month. If it showed 96% after 8 months of use that would be exceptional.
• Are you letting the phone charge to 100%? That is the only time the battery measurements can be recalibrated and some have prevented the phone from charging to 100%, and when it finally gets to charge fully then you will see a large adjustment.
• Where are you seeing the cycle count?
• In the past, Apple has replaced the battery for free in the first year if the health drops under 80%, but it is not documented and you would need to take it to Apple if that occurs for final determination.
• It is expected for the iPhone 13 to not need a battery replacement until it has had 500 charge cycles, under ideal conditions, where you will see the battery health drop below 80%.

iPhone battery and performance - Apple Support

• At any time, you can take the iPhone to Apple for diagnostics, but I don't see any significant problem with your Battery as of now that would warrant any repair.

• What is your Battery Health?
• When was your iPhone purchased?
• On average you will see a 1% drop a month since the purchase date. The drop is not linear and some months will not drop at all and other months will drop more.
• How many Charge Cycles do you have on your battery? You should see about a 1% drop for every 25 charge cycles.