iPhone 18 Pro battery drains quickly with low screen-on time

I had the same problem with my iPhone 18 Pro. I lost around 60–70% of my battery during 8 hours at work. I only sometimes checked a few apps — Weather, Messenger and WhatsApp.

On the first day, during the first configuration, my iPhone restarted 4 times in a row. I lost around 30% of my battery, and it was really hot. The next day, my battery was horrible. Even when my phone was locked, my battery was still draining.

Days 3 and 4 seemed to be better. My battery started working better, but it was only for two days. On days 5–7, my battery started getting worse than on the first and second days.

Of course, I always read a lot of information saying that this is normal. The battery needs more time, but I feel that it is not normal. I understand that the battery can work worse for a few days, but not 1% every 2–3 minutes. My iPhone 13 Pro, which has only 76% battery health, sometimes works better.

I tried everything, but the battery kept getting worse.

Today, I contacted Apple Support. My iPhone had a few diagnostics. I heard different feedback. I heard that it was normal, that my phone needed more time, and that a new version of iOS would improve it. But finally, I heard about a red bug — a software problem, and the software was unstable. This problem had an impact on my battery.

My iPhone is going to be returned. I’m waiting for a new iPhone.

I recommend running diagnostics on your iPhone as well, because this doesn’t look good.

Screen Time is a useless number when attempting to use it to correlate with Battery Usage. For your current device, I doubt any of the background processes have completed yet to index your files. You can see in your first graph that the light gray bars are representing background usage and that is expected when initially setting up or after an any Software Update for about 4 days. With iOS 27, there are additional Siri & Search Optimizations performed that may take a couple of days more. You can see at Settings if the Siri & Search Optimization has ended yet.

As far as any Software Update, Apple provides documentation on what you should expect for a short time after the update, and not only is that increased battery drain, but also heat and some UI lag.

About Apple software updates - Apple Support

After you give it a couple more days for the spotlight indexing and also verified that your Siri & Search Optimization has completed, then post those 2 graphs again along with the top 5 apps that are consuming your battery. That is much more relevant in determining Battery Usage than the Screen Time value.

Disabling Background App Refresh does very little as far as battery drain goes and does not stop Background Activities like many think. The only thing it stops is the UI update to reflect changes and does not stop the other background processes that are performed, especially those used for data harvesting by Social Media apps.

It seems you are being a bit obsessive about battery usage by disabling even useful features on your phone. Just charge your phone all night, every night using the Optimized Battery option and enjoy your phone. A Charge Cycle is not actually how many times you have charged your phone, it is how many times it has drained from full capacity to empty over a period of time. Leaving your phone unplugged overnight is just wasting Charge Cycles as you are relying on your Battery to perform the normal and scheduled background processes intended to be run when you are not using your phone.

What are the top 5 apps consuming your daily battery capacity? Screenshots of your graphics and apps in the battery section will be very helpful in diagnosing the issue.

rhino717 wrote:

Having the same exact issue! Was told by the Genius Bar that it can take two weeks to index and nothing is wrong with my battery.

It absolutely can take up to 2 weeks to finish the indexing in the background if you are not leaving your phone plugged into power and connected to WiFi overnight.

prairie_life wrote:

I've been having the same issues as well. Finally I did enough diagnostics and complaining with support that I'm getting a replacement phone, hopefully this helps because this is unacceptable. I can lose 4% of my battery in 30 minutes while it's completely unused, with all of the optimizations for battery life turned on.

Leave your new phone plugged into power and connected to WiFi all night, every night. There are no optimizations settings on the battery that will have any effect on the Spotlight indexing and the indexing will be draining your battery when unplugged and not in use. I would actually recommend to turn on Optimized Charging as that is beneficial to protecting your battery. If you follow those procedures the indexing should be finished in about 5-7 days, and if not it may be a couple of weeks.

shi292a wrote: Has anyone been able to figure out what’s wrong ? Do we need to get the phone replaced? I started using my phone since 2 days now and it’s completely synced but loses 1% battery every other minute. I’m using WhatsApp and Instagram and maps only. This is very frustrating. My phone was down to 47% with barely any use between 7 am to 5 pm.

Since the background indexing process continues for about 5-7 days following any device setup/update, you have about 3-5 days to go before it has finished. You should expect increased battery drain, increased heat, and some UI lag during that time and it is detailed in this Support Article provided by Apple.

About Apple software updates - Apple Support

The only thing that would be odd is if you did not see that happening. In order to make sure those indexing processes complete quicker, make sure you are charging your phone all night, every night while it is connected to WiFi.

After that 7 days, then you can post the screenshot at Settings > Battery > View All Battery Usage that shows the 2 battery graphs and the top 6 apps consuming your battery, but only after that 7 days.

Certainly WhatsApp and Instagram are going to be top consumers of your battery, and that is typical for all Meta apps. They let you use their apps for free, but they are using your battery to harvest your information to build a Social Graph to increase your value to the advertisers that they sell your data to. That is how they generate billions of dollars every quarter by you using their apps for free and selling very little products for that revenue.

Yes, it improves after indexing, syncing and optimizing finishes. These processes are essential for smooth and efficient operation of your iPhone in the future. Older iPhones held less data, less features etc. So older devices can’t really be compared to a current flagship device.

I’ve had iPhones the last 19+ years since the very first iPhone in 2007. I also own an iPhone 18 Pro Max, purchased launch day. I have a considerable amount of data on my iPhone. I have 35,000+ photos, over 20,000 unread emails and nearly 10 GB of health data from 10 years of Apple Watches. My iPhone 18 PM took just over a week to fully finish indexing.

A best practice is to plug your iPhone into a charger when you go to bed, connect to WiFi and lock Screen every night for the next week. This will allow your iPhone to do a majority of the indexing etc. while you sleep, rather than daytime when you’re trying to use your device.

BerkeA wrote:

Same issue. Battery drains way too fast.

https://discussions.apple.com/content/attachment/6fb899cb-da95-46ba-b1dc-876edfc332e9

Read the Support Document that was provided titled: "About Apple Software Updates". You have confirmed by connecting to the Mac that the Spotlight processes are still being performed and expected from your screenshot showing the update 2 days ago. Expect this to take a week to finish when connected to both WiFi and Power overnight, and if not it could take even longer to complete.

I have tweaked the crap out of my phone.

• BT Off
• Phone in airplane mode with Wifi on
• no eSIM installed yet
• All factory apps
• Clean factory setup, did not carry over from old device
• Powered on for 5 days
• Adaptive power on
• TrueTone off
• Siri Off
• Location services set to only find my...
• display brightness set to about 1/3.
• Always on display off
• lock after 30 seconds
• Fully updated

100% charged and not use at 4:11PM yesterday, this morning, 69%......

So decided to drain out the battery by watching an AppleTV movie..

Results, 2hr movie using 69% of the battery? How are you supposed to get 45hours worth of video watching as per Apples claims on iPhone 18 pro.

Lots of people reporting battery issues on the 18 Pro...

I have 18 pro max coming from a 2-year-old iPhone 16 pro max and the battery performance is TRASH !!

It loses 1 percent every like 2-3 minutes with normal usage. 16 pro max was holding up the whole day with 20+ percent left at the end of the day, this 18 pro max can’t hold up to the middle of the day !!

I have the phone 11 days ago and indexing was completed by day 3 !

I contacted apple support and they ran diagnostics and told me that everything hardware is good and when i shared screen with them, they admitted that something is wrong but they told that it may be a software issue !!

I did all what they told with nothing changed;

• Force restart
• Reset network settings
• Update to latest IOS
• Connecting the phone to charger at night with wifi connected
• Adaptive power on

NOTHING WORKED !

Looks ok to me. You chose to recharge at 6pm at 40% Why not leave it til bed time?

And you only charge to 80%. Absolutely pointless in a busy phone,

If you had charged to 100% overnight using optimised charging you would have a full day's battery and a healthy charge at bedtime

Same issue. Battery drains way too fast. I tried connecting to my mac to check for the Indexing Progress, it says:

debug	09:23:46.295885+0200	Preferences	PipelineCompleteness: hidden
debug	09:23:46.324350+0200	spotlightknowledged.updater	fetchPipelineCompleteness: display=hidden days=1 percent=1.000000 calculatedAt=2026-09-23 05:14:31 +0000

I've been having the same issues as well. Finally I did enough diagnostics and complaining with support that I'm getting a replacement phone, hopefully this helps because this is unacceptable. I can lose 4% of my battery in 30 minutes while it's completely unused, with all of the optimizations for battery life turned on.

A full days use starting at 85% seems reasonable.

I suggest using optimised charging to 100% instead of charge limit and charge every night while you sleep

As a longtime Android user coming from a Pixel 9 Pro XL to my first iPhone (18 Pro Max), I’m surprised by how fast the battery drains. With minimal use, dropping to 65% by 6:00 PM feels excessive. While I hope performance levels out after a few days of indexing, the experience so far has been underwhelming—especially with iOS feeling a bit behind on several practical software features I took for granted on Pixel.