Before changing any setting, open Settings > Battery and go into Battery Health: the maximum capacity figure decides the rest of the path (Solution 1). Above 85%, the battery is fine and the drain comes from a setting or a specific app, which the per-app usage screen points to in a minute (Solution 2). Between 80% and 85%, the battery has started to age and the adjustments in Solutions 3, 4 and 5 still make a real difference day to day. Below 80%, no setting brings back the lost runtime: 80% is the threshold Apple itself uses as the reference for a consumed battery, and Solution 9 explains how to decide on a replacement. If the drain started suddenly and battery health is good, the likeliest cause is an app with location set to Always (Solution 4), or an iPhone that has just updated and is still reindexing, which settles down within a few days (Solution 6).
What causes this problem
- Normal battery ageing, which loses capacity with every charge cycle and reaches a point where the same routine no longer fits in a day.
- An app with its location permission set to Always, keeping GPS active in the background.
- A recent iOS update, which reindexes photos and files in the background for a few days and makes the drain look far worse than it will end up being.
- The screen staying on for long stretches, at high brightness, with auto-lock set to a long interval.
- A weak mobile signal, which makes the phone raise its antenna power to hold the connection and burns battery quickly.
- A faulty app stuck in the background, still consuming even though you never open it.
- Open Settings > Battery and let the screen load the 24-hour and last-days graphs. Without that data you will be working on guesswork.
- Notice when the drain started. Was it after an update, after installing a new app, or after a trip somewhere with poor signal? Each answer points to a different solution.
- Tell fast drain apart from unexpected shutdowns. A phone that switches off by itself at 20% or 30% on the indicator has a battery at the end of its life, and that case goes straight to Solution 9.
- Have your Apple ID password at hand. It is asked for during some setting changes and during a restore.
- If you are going to consider a battery replacement, first check whether the phone is still under warranty or covered by a plan, because that changes the cost.
Solutions, in the order to try them
1Read the Battery Health screen and understand the figure
This comes first because it separates two worlds. Maximum capacity shows how much the battery still holds compared with the day it was new. A battery at 90% capacity has, in practice, 90% of the original runtime, and no setting brings back the 10% that has gone. Apple treats 80% as the threshold: above that the battery is considered to be in normal condition, below it the battery is considered consumed and replacement comes into play. That number falls naturally with use and is not a defect.
- Open Settings > Battery and tap Battery Health, inside that screen.
- Note the Maximum Capacity value. It is the most important piece of information in this guide.
- Check whether any message about peak performance capability appears. A notice that the battery was affected by an unexpected shutdown, or a service recommendation, confirms that a replacement would solve it.
- On more recent models, the charge cycle count appears under Settings > General > About. It helps show whether the battery is young or has already been through a lot.
- With the number in hand, follow the path from the summary: above 85%, go to Solution 2; below 80%, go straight to Solution 9.
2Find out which app is draining the battery
The iPhone keeps a detailed record of how much each app used, and it almost always points to the culprit beyond doubt. The detail that matters is the split between screen-on time and background time: an app you used for two hours has earned the right to have used a lot, but one you barely opened that sits at the top of the list is doing something you did not ask for.
- Open Settings > Battery and let the graphs load.
- Switch between the last 24 hours view and the last days view. The longer view shows patterns that an unusual day hides.
- Tap the option that shows activity by app and compare screen time with background time.
- Note the two or three apps with the most background activity relative to actual use. They are the target of the next solutions.
- If an app shows absurd consumption with little use, delete and reinstall it. That ends any stuck process it left running.
3Adjust the location permissions
Location set to Always is the biggest source of invisible drain on an iPhone. The app wakes the GPS every so often, even when you are nowhere near it, and that costs dearly. Very few apps genuinely need that permission: navigation with an active route, fitness tracking and little else. For everything else, While Using delivers the same experience without the cost.
- Open Settings > Privacy and Security > Location Services.
- Go through the list and switch everything set to Always over to While Using the App, except what you genuinely need tracking in the background.
- Turn location off entirely for apps that have no reason at all to know where you are.
- At the bottom of the list, go into System Services and turn off items you do not need, such as location-based ads.
- Give it a day or two before judging the result: the battery graph needs that time to reflect the change.
4Control Background App Refresh
This feature lets apps fetch new content on their own, even when closed, so they are up to date when you open them. On two or three apps it is useful; on fifty, it is a tap left running. Turning it off does not stop message notifications arriving, because those come through a different route.
- Open Settings > General > Background App Refresh.
- Turn off individually the apps that showed up at the top in Solution 2 without you using them.
- If you prefer a single decision, change the option at the top to work on Wi-Fi only, or turn everything off and re-enable later only what you miss.
- Messaging apps do not need this feature on to alert you to new messages.
- Check whether any app you do not recognise is on the list. It is worth deleting anything you have not used in months.
5Cut what the screen costs you
The screen is the biggest battery consumer on any phone, and it is where adjustments pay off immediately. There is no need to leave the phone dim or uncomfortable: changing auto-brightness, lock time and always-on display already moves the number at the end of the day, especially for anyone using the phone outdoors.
- Under Settings > Accessibility > Display and Text Size, confirm that Auto-Brightness is on, so the phone does not hold high brightness pointlessly in a dark room.
- Under Settings > Display and Brightness, reduce Auto-Lock to 30 seconds or 1 minute.
- On the same screen, if your model has the always-on display option, turn it off and compare the drain over a few days.
- Switch on Dark Mode, which helps on models with an OLED screen.
- Turn off motion effects under Settings > Accessibility > Motion if you want an extra gain.
6Update iOS, and give it a few days after updating
These two go together and confuse a lot of people. Updates often carry fixes for abnormal drain, so keeping the system current is worth it. At the same time, right after an update the iPhone reindexes photos, messages and files in the background, and the drain looks visibly worse for a few days. Replacing the battery inside that window is money wasted.
- Open Settings > General > Software Update and install whatever is available.
- Update your apps from the store as well, because an outdated app can clash with the new version of the system.
- If you have just updated, leave the phone charging overnight and connected to Wi-Fi for two or three days before drawing conclusions.
- After that period, go back to the Battery screen and compare the graphs. If the drain is still high, move on to the next solutions.
- Do not skip this step out of fear of updating: older system versions accumulate drain bugs that have already been fixed.
7Use Low Power Mode and optimised charging
Low Power Mode is not just for emergencies. It reduces background activity, visual effects and automatic mail fetching, and plenty of people leave it on all the time without noticing any difference in use. Optimised charging, on the other hand, does not extend today's runtime but slows the battery's ageing, which pushes back the replacement in Solution 9.
- Open Settings > Battery and turn Low Power Mode on. It switches itself off once the charge passes 80%, so it is worth adding the shortcut to Control Centre to switch it back on quickly.
- In the same battery area, confirm that optimised charging is active, so the phone holds at 80% and completes the charge near the time you usually wake up.
- If your model offers an adjustable charge limit, consider keeping it at 80% or 90% if you spend the day near a socket.
- Avoid leaving the phone charging in a car in the sun or under a pillow: heat is what degrades a battery most.
- Prefer normal-speed charging day to day and save fast charging for when you genuinely need it.
8Restart, force restart and, as a last resort, restore
A stuck system process drains battery without showing up properly in the app list. A normal restart resolves a good share of those cases. If the drain is clearly abnormal, battery health is good and nothing above helped, restoring the phone and reinstalling from a backup clears out faulty settings inherited from older devices. Make a fresh backup first: the restore erases the phone's contents.
- Switch the iPhone off and on normally and use it for a day.
- If it does not improve, do a force restart: press and release volume up, press and release volume down, then hold the side button until the Apple logo appears.
- If it persists, make a full backup to the cloud or to a computer and confirm that it finished.
- Restore the phone and choose to recover from that backup.
- If the abnormal drain returns right after restoring the backup, the problem is in an app or setting that came with it: set the phone up as new and reinstall apps gradually.
9Decide when to replace the battery
This is the solution for anyone who saw a figure below 80% in Solution 1, and there is no point putting it off with settings. Below that threshold the battery is considered consumed, the runtime does not come back, and the system may reduce the phone's performance to avoid sudden shutdowns. A replacement costs a fraction of a new phone and restores the original runtime, which makes an iPhone that is a few years old perfectly usable again.
- Consider a replacement if maximum capacity is below 80%, if a service message appears on the battery health screen, or if the phone switches off by itself with charge left on the indicator.
- Check first whether the phone is under warranty or covered by a plan, because the replacement may then cost nothing.
- Go to the brand's authorised service or a repair shop you trust. A battery of dubious origin tends not to last and can make the system stop showing the health information.
- Make a full backup before handing the phone over, as a precaution.
- If capacity is between 80% and 85% and the phone is several years old, a replacement is still worth it and usually delivers more than any adjustment in this guide.
Applies to
| System | Status |
|---|---|
| iPhone on iOS 16 and later | Confirmed |
| iPhone on iOS 15 or earlier | The battery health screen exists, but some settings sit in different places and the charge limit is not available |
| iPad | There is no Battery Health screen; the location, background and screen steps apply the same way |
Menu names can change slightly between versions. If a step above does not match what you see on screen, the official support page from the manufacturer has the most current wording for your version.
Frequently asked questions
Last checked: Sep 26, 2026 · We review this guide whenever the manufacturer changes the process.