iPhone 13 Battery Health Drop

sujayshah wrote:

September end last last year.

iPhone battery capacity drops an average of 1% per month. So it has been 8 months. Thus 93% is about where it should be.

Batteries are consumables; they lose a little capacity every time they are discharged, then recharged. On average this works out to about a 1% loss for every 25 “full charge cycles”. As one example, if you charge the phone overnight, every night (and that is what you should do; it is a best practice), it starts the day at 100%. If it drops to 20% by the end of the day before you charge it again overnight that counts as 0.8 full charge cycles (20% to 100%), or about 24 full charge cycles per month of use. For this example your battery capacity will lose about 1% per month. Of course, if the end-of-day level is higher than 20% the capacity loss will be a little less, and if it is lower than 20%, or you charge it during the day, the capacity loss will be higher.

Once the capacity drops below 80%, or if there is a message in Battery Health that the battery is not meeting peak performance expectations, it’s time to change the battery→iPhone Battery Replacement - Official Apple Support

The absolute best way to get maximum use on a charge, as well as slow the decline of battery capacity long term is to enable Optimized Battery Charging (Settings/Battery/Battery Health) and charge the device overnight, every night. The battery will fast charge to 80%, then pause. During the nighttime pause the phone will use mains power instead of battery power, allowing the battery to “rest”, and thus reducing the need to charge the battery quite as often. The phone will resume charging to reach 100% when you are ready to use your phone; it will “learn” your usage pattern. If you enable iCloud Backup (Settings/[your name]/iCloud - iCloud Backup) the phone will back up overnight also, assuring that you can never lose more than the current day’s updates. Here's more information→About Optimized Battery Charging on your iPhone - Apple Support

That’s about right. And 99%, if it just changed, means 99.9% because the gauge does not round, it just drops the tenths.

Batteries are consumables; they lose a little capacity every time they are discharged, then recharged. On average this works out to about a 1% loss for every 25 “full charge cycles”. As one example, if you charge the phone overnight, every night (and that is what you should do; it is a best practice), it starts the day at 100%. If it drops to 20% by the end of the day before you charge it again overnight that counts as 0.8 full charge cycles (20% to 100%), or about 24 full charge cycles per month of use. For this example your battery capacity will lose about 1% per month. Of course, if the end-of-day level is higher than 20% the capacity loss will be a little less, and if it is lower than 20%, or you charge it during the day, the capacity loss will be higher.

Once the capacity drops below 80%, or if there is a message in Battery Health that the battery is not meeting peak performance expectations, it’s time to change the battery→iPhone Battery Replacement - Official Apple Support

The absolute best way to get maximum use on a charge, as well as slow the decline of battery capacity long term is to enable Optimized Battery Charging (Settings/Battery/Battery Health) and charge the device overnight, every night. The battery will fast charge to 80%, then pause. During the nighttime pause the phone will use mains power instead of battery power, allowing the battery to “rest”, and thus reducing the need to charge the battery quite as often. The phone will resume charging to reach 100% when you are ready to use your phone; it will “learn” your usage pattern. If you enable iCloud Backup (Settings/[your name]/iCloud - iCloud Backup) the phone will back up overnight also, assuring that you can never lose more than the current day’s updates. Here's more information→About Optimized Battery Charging on your iPhone - Apple Support

Hello, kamrul420.

The battery in your iPhone will age and at different rates, at different times. This is expected and does not indicate an issue with the iPhone or the battery. Typically, Apple advises replacement once a battery reaches less than 80% of its maximum capacity. Yours is still well above that. The screenshot shows it is working at Peak Performance, which is also a good sign.

Learn more about battery life and the expected chemical aging here: iPhone Battery and Performance - Apple Support.

Let us know if we can help with anything else at all. Thanks and have a fabulous day!

Hello Lawrence.

to keep my post short I avoided TMI. I’ll now expand on my original post.

If a Lithium-Ion battery is charged to 100% and then either not used immediately or lightly used so the charge state stays above say 90% for some time, the battery will prematurely age and it’s health will drop.

Apple acknowledges this here;

Batteries - Maximising Performance - Apple (UK)

see this statement;

Do not fully charge or fully discharge your device’s battery — charge it to around 50%. If you store a device when its battery is fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge. Conversely, if you store it fully charged for an extended period of time, the battery may lose some capacity, leading to shorter battery life.

This statement relates to storing a phone however in my opinion it is a disingenuous statement which only eludes to the truth. 100% is 100% and how long is storage for ‘some time’? If 10 days does some damage the surely so does 10 hours or even 10 minutes, obviously to a lesser extent but the cumulative effect will be similar.

A brief Google search will show many commentators who advise against 100% charging.

Perhaps it’s in a phone manufacturers interest to avoid the full truth in the interest of sales and replacements.

I’m an electronic engineer in Industrial Automation and Control where battery back-up systems (DC-UPS) utilising Li-Ion are commonly used.

I’ve also driven Tesla’s since 2016, my house is powered by Tesla Powerwalls and my wife drives another EV.

I have a huge investment in Li-Ion and consequently need to understand them.

I have made a study of maximising battery life and have investigated the chemistry and chemical reactions in Li-Ion batteries.

If you have been charging consistently to 100% I’m amazed that your battery health is still so high, perhaps the exception that proves the rule.

Thank you for your advice but I’d rather follow my experience.

Regards

Malcolm.

The battery health percentage on your iPhone is a measure of the battery capacity relative to when it was new. It’s normal for this to slowly decrease over time. However, if you’re noticing a rapid drop, it might be due to the way you’re using or charging your device, or it could potentially be a software issue.

Here are some general tips to maintain your battery health:

1. Update to the latest software: Always make sure your device is running the latest version of iOS. Future updates may offer further improvements.

2. Optimize your settings: Some features can affect battery life. You might want to turn off dynamic wallpapers and motion effects, reduce screen brightness, or use Wi-Fi instead of cellular data.

3. Avoid extreme ambient temperatures: Your device is designed to perform well in a wide range of ambient temperatures. Exposure to extreme temperatures can affect battery health over time.

4. Understand battery usage: In Settings > Battery, you can check which apps are consuming most of your battery power.

5. Enable Optimized Battery Charging: Go to Settings > Battery > Battery Health and turn on Optimized Battery Charging. This feature learns your daily charging patterns and can slow down battery aging.

If the battery health continues to decrease rapidly after trying these tips, it might be worth reaching out to Apple Support. They can run a remote diagnostic on your battery and see if there might be a hardware issue.

After 6 months dropping to 95% (and if it has just dropped, actually to 95.9%) is normal. Your iPhone SE battery was better than normal.

A battery is a chemical device, and chemistry is generally pretty variable and uncertain, as well as being analog, not digital. Apple specs the battery capacity to remain above 80% for 500 full charge cycles, but that is a minimum requirement; there is no published maximum expected capacity. So sometimes batteries will perform much better than that minimum specification, and sometimes the change in maximum capacity won't be linear. There is no way to predict in advance what the real-life performance of any specific battery will be.

All iPhones have a specification for the battery. As an example, for the iPhone 14 Pro that is 3200 milliampere-hours (MaH). So the battery monitor is calibrated for 100% at that value. But there are variations in manufacturing, so some batteries will have less capacity, and some will have more. Suppose your battery had, say, 3520 MaH capacity (10% over standard). That would still show as 100% (even though it was actually 110%), but as it aged the health would stay at 100% until it fell below 3200 MaH. This would appear to you as if the battery had fabulous life, until suddenly it didn’t.

Then you don't know how long that phone had been sitting on a shelf not being charged. iPhone 13 was released in 2021, almost 3 years ago. If that phone sat around not being charged, its battery health was already degraded by the time you got it. Lithium iON Batteries which are not charged for extended periods of time lose battery health.

Let's see what it shows for warranty, by going to Settings > General > About and look at the box under Serial Number. Tap it and if my assumption is correct, the phone's warranty may have already expired. iPhone warranty begins the day an iPhone leaves Apple or an actual Apple Authorized Reseller. A gadget shop is not an authorized reseller.

funsutton1 wrote:

I have had my iphone roughly one year and the battery health just now dropped to 99%. It's because I never keep charging the phone when it has reached 100%.

I set an alert on my phone when it reaches 100% and disconnect it immediately. I never charge it overnight and let it sit on the charger when fully charged.

Totally unnecessary. The phone itself has a charge monitoring chip in it, and stops charging at 100%. And it’s actually BETTER for the battery to leave it in after it stops charging, because that way the power to run the phone comes from the external power source rather than the battery.

Either you were just lucky that your battery exceeded the minimum capacity specification and started out life over 100% (probably around 110-115%), you use the phone very little, or your battery gauge is broken. If you have a Mac the app Coconut Battery can tell you details about the original battery capacity, the number of charge cycles, and the current state of the battery.

There's no solution. You purchased a phone manufactured long before you acquired it. You have no warranty and the Battery Health has declined naturally. Use and enjoy the phone and when Battery Health dips to 80%, which it will at some point, you then pay Apple to replace the battery.

You are missing one factor: Whether the phone runs on battery 100% of the time, or uses external power some of the time, which reduces the number of charge-discharge cycles. When you charge overnight, the battery will fast charge to 80%, then pause. During the nighttime pause the phone will use mains power instead of battery power, allowing the battery to “rest”, and thus reducing the need to charge the battery quite as often. The phone will resume charging to reach 100% when you are ready to use your phone; it will “learn” your usage pattern. If you enable iCloud Backup (Settings/[your name]/iCloud - iCloud Backup) the phone will back up overnight also, assuring that you can never lose more than the current day’s updates.

The 100% factor is the battery should not be kept at 100%, not that it should never be charged to 100%. Follow Apple’s guidance to charge overnight with optimized charging enabled it will only be at 100% for a short time, as it will start discharging as soon as you discount it.

There is a fundamental difference between an EV car and an iPhone; you can use an iPhone while it is plugged it, and it can use external power rather than the battery. You can’t use your Tesla when it is plugged in unless you have a VERY long extension cord.

I purchase my iPhone 13 Pro in June 2022. Today, after more than 1 year it’s battery health has just dropped to 98%.

I rarely charge it above 80% with the help of an App called Battery Alarm. I also have charging optimised and various settings adjusted to save battery life like Push emails and Background App refresh switched off

Rechargeable batteries do not like charging above 80/90%, it kills their lifespan.

The biggest error most people make is charging overnight.

My phone cost me £1000. Why would I intentionally damage it?

I also drive an EV and follow exactly the same principles.

You should contact Apple for help if your phone is getting hot. You may have a hardware issue. You can start here.

Contact - Official Apple Support

That is not normal. Make an appointment at the Genius Bar to have it diagnosed.

Genius Bar Reservation and Apple Support Options - Apple

I'd take the battery health indication with a pinch of salt. It might give you a very general idea of your battery's condition at a given point of time, but it's by no means a 100 percent reliable tool to measure the battery's performance and the speed at which it deteriorates in real time. That said, your battery health might have been below the level your iphone indicated for some time without you knowing it until it "woke up" and started catching up with reality. My iphone 13 lost 1 percent after the first 6 months. Previously, my iphone 11 was stuck at 100 percent for 12 months, before the battery health started going down. But when it did, it kept going down by 2 percent each month. So the best way to assess the battery health is to use your experience in every day use.

An average iPhone that is 6 months old, as yours is, would be at 94%. So your phone’s battery performance is better than average.

Also, note that the displayed value does not include fractions, so when it goes from 98% to 97% it has actually gone from 98.0% to 97.9%. It has not dropped a full percent.

Read my post right above yours for more detailed information.