iPhone 15 Pro Max battery drains 10-17% overnight in Airplane Mode

How many hours is overnight? Airplane Mode is not a sleep or shutdown mode. Apps and system processes can still consume power. Also, WiFi and Bluetooth can remain enabled in Airplane Mode, so the airplane icon alone does not establish that the phone has no wireless connections. Check their actual settings.

Use Airplane Mode on your iPhone, iPad, Apple Watch, and Apple Vision Pro - Apple Support

Use Bluetooth and Wi-Fi in Control Center - Apple Support

Connected activity, if Wi-Fi remained on Apps showing background usage or notifications during the period. Airplane Mode can coexist with an active Wi-Fi connection, and notifications can wake the device.

“Home & Lock Screen,” frequent screen wakes, or actual screen on use. Apple notes that notifications waking the device contribute to consumption.

System work rather than an app Background work following an iOS update or device setup. Apple advises allowing a few days after an update because some tasks continue in the background and can affect battery life.

In my case it took my iPhone 18 Pro Max over a week to finish indexing, syncing etc. about 280 GB of data. How much data is on your device and how full is your devices storage?

Home & Lock screen usage indicates background processing to index the files. This is most noticeable for about 5 - 7 days following an update, but not unusual for any indexing process to be scheduled while you are not using your phone. Your phone is always working, even when not connected to the internet and is never completely idle.

It is debatable whether your battery is 100% healthy, it certainly is normal though. You are halfway to needing a replacement once it drops below 80% Battery Health. Nothing wrong with your battery showing the Battery Health of 90% with 418 charge cycles, it just does not have the capacity as it did when it was 100% Battery Health.

In addition to Bob Timmons's excellent advice, I would add that it has been my observation that iPhones work less well if you disconnect them from data.

Put the phone on charge overnight, connected to WiFi. It will do all the housekeeping it needs to do, including an iCloud backup (make sure that's turned on). In the morning, it will be ready to go.

There is little to be gained by trying to micromanage the battery. It doesn't lead to longer battery life, just frustration and anxiety.

relying on a charger every single night shouldn't be necessary to mask an abnormal 10%–17% standby drain.

Maybe, but if you want to stop the overnight drain, leave the iPhone connected to the power supply when possible.

A healthy idle standby in Airplane Mode with no apps running should only drop 1% to 5%, so plugging it in every night is a workaround rather than a solution for an underlying system loop.

I don't think you will find the answer that you want here. You might want to let Apple know about your opinion.

Feedback - iPhone - Apple

suyoj wrote:

is that feasable?While plugging it in overnight works fine when I’m at home, relying on a charger every single night shouldn't be necessary to mask an abnormal 10%–17% standby drain.

If I’m traveling or away from an outlet overnight, losing nearly 20% of my battery while the phone sits completely idle in Airplane Mode is a real issue.

I carry a portable battery charger pack, they are quite small nowadays, to charge my iPhone when necessary while traveling. I actually have two: a very small one that is fine for the iPhone, and a larger one that can power and charge a laptop as well. I almost never use these battery packs, however, because I can always charge things overnight (including on an airplane).

A healthy idle standby in Airplane Mode with no apps running should only drop 1% to 5%, so plugging it in every night is a workaround rather than a solution for an underlying system loop.

I just put my iPhone in Airplane Mode and noticed it stays on WiFi when in Airplane Mode. BlueTooth also stays on. So even in Airplane Mode, the iPhone may be backing up to iCloud overnight, connecting to other cloud storage (I have Dropbox also), updating apps (mine is on auto update for apps), and who knows else given that many apps and services check online overnight for updates, status, etc. My old work phone was a managed device, it used a lot of energy overnight for that stuff (which thankfully I don't have to worry about with my personal phone). Every morning when I look at my phone there is a slew of notifications, those all are checked for or are pushed to the phone, using energy. Mail is being checked in the background, even if you have quit the Mail app. Another user of energy and power from the phone is Location Services, which are active for many processes and apps, unless you go through them all and force it to be off (some cannot be forced off however). My Apple Watch is doing sleep tracking all night and interacting with the iPhone via Bluetooth or WiFi, I don't know which, all night long. The Watch also auto updates its apps, which involves ongoing jabbering between it and the phone. All this stuff uses energy from the battery, which is why connecting to some sort of power source overnight is a must. You might be surprised at how much your phone is doing overnight. I found this out when doing some overseas traveling and was monitoring it to stay on top of roaming and data use charges. Remarkably large amounts of data are coming to (and leaving) your phone every night, more than once each night. You can see this in fact on your cellular provider some time by disconnecting from WiFi at night and check the cellular data traffic that was recorded instead, it's enormous. That traffic goes either through WiFi or cellular (if WiFi is off) every night is one reason batteries run down more than people expect.

Your phone is never completely idle. There is usually something going on, even if you are not aware of it, and the settings don't indicate it.

Why are you not connecting the phone to the power supply adapter and leaving it connected all night.....every night?

When to charge your iPhone or iPad - Apple Community

is that feasable?While plugging it in overnight works fine when I’m at home, relying on a charger every single night shouldn't be necessary to mask an abnormal 10%–17% standby drain.

If I’m traveling or away from an outlet overnight, losing nearly 20% of my battery while the phone sits completely idle in Airplane Mode is a real issue. A healthy idle standby in Airplane Mode with no apps running should only drop 1% to 5%, so plugging it in every night is a workaround rather than a solution for an underlying system loop.

What is your current Battery Health? iPhone 15 Pro Max was released in 2023, 3 years ago. Batteries don't last forever and when the health dips to 80% or lower, the battery needs to be replaced. Open Settings > Battery > Battery Health - is it 80% or lower?

90% with 418 cycle count