Is your iPhone not charging after iOS 27 update, or charging very slowly? This is a sadly common problem for Apple customers, and the complaint spikes in the weeks after a major software release like iOS 27. Before long the battery will be empty and you’ll be stuck with the world’s most expensive chopping board.
This isn’t a problem that’s unique to Apple products: for various reasons the charging port and cable are almost always a weak point on tablets and smartphones.
Your iPhone’s charging port – USB-C on iPhone 15 models and later, Lightning on iPhone 14 models and earlier – is open to the air and therefore susceptible to dust getting inside and clogging up the connections; the bit just behind the head of the charging cable often frays. And this all assumes that there are no problems with the plug or your power outlet, and that the iPhone’s battery unit is still performing properly – neither of which are safe assumptions.
In this article we walk you through a range of troubleshooting tips that will help you establish why your iPhone won’t charge after iOS 27 update, and offer solutions that will fix many of these issues either permanently or temporarily. If all else fails, we explain your consumer rights, and offer some advice about getting Apple to step in and repair a malfunctioning device for you.
1. Absolute basics
Let’s check the absolute basics first.
Make sure the cable is plugged firmly and fully into the iPhone, that the other end is plugged firmly into the power adapter plug, and that the adapter plug is plugged firmly into the wall outlet. Apple starts in the same place with an iPhone that won’t charge: a wall outlet, firm connections the whole way along, and a different outlet if you have one to hand. (If you’re charging via a Mac rather than through a wall plug, jump to the next step.)
Make sure the power outlet is switched on. Yes, we know – but it’s still worth checking.
2. Charging via a Mac
A computer is rarely the quickest way to fill a battery. Plug into a machine or a hub that already has other devices hanging off it and the maximum power output drops, because everything attached is drawing on the same budget. Car ports are no better.
The iPhone may warn you if the Mac isn’t able to charge it, but in our experience that often doesn’t happen: sometimes the charging icon appears yet the percentage doesn’t increase, or does so at a glacial rate.
If you’re charging via a MacBook, make sure the MacBook itself is plugged in: depending on the settings you’ve selected, there may be problems if the laptop is trying to preserve battery power. And whichever Mac you’re using, be sure to plug into the Mac itself rather than a USB-connected keyboard or similar.
As in the previous step, make sure the cable is attached firmly to the Mac. Similarly, make sure the Mac is switched on and awake. Technically, you should be able to charge from a sleeping Mac provided it was awake when you plugged your device in – if it then goes to sleep the charging should continue. But let’s play it safe here.
3. Stop using the iPhone!
Are you using your iPhone at the same time as charging it? Any charge you gain will be set against the loss incurred through working the processor and screen. Graphics-heavy games, processor-heavy apps, the camera, video streamed at full brightness – all of them slow the charge while they run.
Charging via a Mac in particular (see previous step) is almost always a dead loss if you have the screen powered on at the same time – a sad fact we discovered after trying to use an iPad Air 2 as a spare screen at work. Despite being plugged into the main Mac and only having a (continually refreshing) web page open, the iPad was always dead by lunchtime. You’re losing charge quicker than you’re gaining it.
In other words, try switching the iPhone off – at least power off the screen – and see if that helps.
4. Check the charging port for detritus
Remove the cable from the charging port and take a look at the connector at the bottom of your device. Every iPhone that can run iOS 27 has either a USB-C port (iPhone 15 models and later) or a Lightning port (iPhone 14 models and earlier). Whichever you have, the same principles apply.
Clear any debris out of the port, then plug the cable back in firmly. Check here before you spend money on an iPhone not charging after iOS 27 update: lint compacts at the bottom of a port over months, and it will hold the connector just short of contact.
5. Are you using the right kind of charger?
The old 5W, 10W and 12W plugs are long gone. Pair a modern iPhone with the wrong adapter and you can lose an afternoon diagnosing a fault that was never there.
For fast wired charging you want a USB-C Power Delivery charger, with a USB-C cable on iPhone 15 models and later, or a USB-C to Lightning cable on iPhone 14 models and earlier. A wired charger of 7.5W or less will crawl. So will a wireless charger under 10W, such as a Qi1 pad. And with a USB-A charger, iPhone 15 models and later cap out at 7.5W anyway.
An iPhone 8 or later reaches 50 percent in around 30 minutes on an Apple 18W or greater USB-C Power Adapter, or a comparable third-party unit that supports USB Power Delivery. iPhone 12 and later need 20W or higher. iPhone 17, iPhone 17 Pro and iPhone 17 Pro Max get to 50 percent in around 20 minutes on a 40W adapter or higher.
If you’re not sure which Apple power adapter you have, the wattage is printed on the top or bottom of the plug. Label it once you know, and you’ll never grab the wrong one again.
6. Check your charge limit before blaming the update
Here is the one to check before you buy anything. If the percentage climbs and then parks at 80, an iPhone won’t charge after iOS 27 update because you told it not to.
Optimized Battery Charging reduces the time your iPhone spends fully charged, and delays charging past 80 percent when your iPhone predicts it will be connected to a charger for an extended period. When it’s active, a notification on the Lock Screen says when your iPhone will be fully charged. If you need it charged sooner, touch and hold the notification, then tap Charge Now.
On iPhone 15 models and later there’s also Charge Limit, which stops charging at a level you set:
- Open the Settings app, then tap Battery.
- Tap Charging.
- Choose an option. You can choose a charge limit between 80 percent and 100 percent in 5 percent increments. When the charge limit is 100 percent, Optimized Battery Charging is available.
On iPhone 14 models and earlier, open the Settings app, tap Battery, tap Battery Health & Charging, then turn Optimized Battery Charging on or off.
The same screen flags chargers, too. A Slow Charger message appears on the Lock Screen and in Battery when a higher-wattage charger would improve things. An Incompatible Charger message appears when iOS sees a charger connected but not charging. It will also show you whether charging went on hold because the battery got too warm.
7. Waiting, restarting and resetting
Leave it plugged in for half an hour before going any further. That costs nothing but patience, and it clears a surprising amount.
If it still won’t power on, or the screen just shows a battery icon, force restart it. Press and quickly release the volume up button. Press and quickly release the volume down button. Press and hold the side button until the Apple logo appears. Then give it another half hour on the charger.
You may see an alert when you plug in your device saying the accessory isn’t supported or certified. In which case you know the problem is the charging equipment. Connect the device straight to the charger with nothing in between, clear the port, restart the iPhone, try a different cable or charger, and check you’re on the latest version of iOS. We’ll try swapping out various parts of the charging setup in the next step.
8. Work out which component isn’t working
At this point we appear to be headed into the realms of component failure. But if we’re lucky, the part that is misbehaving may be cheap to replace. Fingers crossed.
Set up the iPhone, cable and plug as before – keep everything the same – but this time, plug into a different power outlet (or into a different USB port on your Mac). If it starts working, congratulations! Your power outlet (or USB port) is broken. Okay, that’s not ideal but at least you know.
If it still won’t charge, keep everything the same but this time use a spare charging cable or borrow one from a friend. There are alternatives to Apple’s own cable: you can buy a third-party MFi-certified cable.
Finally, do the same with the plug adapter on the end of the charging cable.
If your cable or power adapter is at fault, in almost every case we would strongly advise paying for a new unit instead of attempting a repair – the words "amateur repair" and "mains power" should never appear in the same sentence.
If none of these substitutions work, it’s most likely your iPhone that’s misbehaving. If that’s the case, we need to get help from the professionals.
9. Get Apple to fix your iPhone
First of all, be warned that the Apple representative who deals with your issue will ask you to repeat some or all of the steps we have outlined previously. Try not to lose your patience!
Many of us prefer to speak to an Apple employee face to face while discussing tech problems, but it may be inconvenient to get to an Apple Store, or to make an appointment there. Instead you may choose to get in touch with Apple support, but you will most likely be asked to send or take in your iPhone for a service, and at that point you just have to sit back and wait for Apple’s diagnosis.
If you’re still in warranty, this should remain financially painless. The one-year warranty covers the battery as well, on top of whatever rights your local consumer law gives you. Out of warranty, you may be able to claim for the repair through any insurance you took out specifically to cover the iPhone, or even a good quality of home and contents insurance.
If not, consider whether the repair is worth the cost. Check the latest prices for the model you would choose as a replacement. Would you have been thinking about an upgrade soon anyway?
Before you get that far, though, go back to step 6. An iPhone not charging after iOS 27 update is far more often a charge limit somebody set and forgot than anything a technician needs to open up.