Solve this by elimination, swapping one part at a time: port, cable, power supply and socket. The number one cause is pocket lint packed into the bottom of the charging port, and cleaning it (Solution 1) fixes a huge share of cases people assume are the battery. Then change the cable (Solution 2) and the power supply (Solution 3), because those three steps cover nearly everything. If the device shows no sign of life, force a restart (Solution 4) and leave it charging for half an hour untouched (Solution 5). Only after all of that is it worth looking at Battery Health (Solution 7), and remember that slow charging or stopping at 80 per cent is usually normal behaviour, not a fault.
What causes this problem
- Pocket lint packed into the bottom of the charging port, stopping the connector from reaching the contacts. It is the most common cause of all.
- A cable with broken internal wires near the connector, which charges intermittently before failing completely.
- A weak or faulty power supply, or a computer and car charger USB port that delivers very little current.
- A battery at the end of its life, which holds little charge and sometimes shuts the phone down even while showing a percentage.
- An automatic pause for temperature: the iPhone stops charging when it gets too hot and resumes on its own once it cools.
- A system freeze, where the screen stays dark and the phone looks dead even though it is plugged in.
- Watch what happens when you plug it in: does the lightning bolt appear on the battery, does it vibrate, does the screen flash, or does nothing happen? Each answer points at a different part.
- Set aside a spare cable and power supply for the tests, ideally original or certified ones. Testing with unknown gear proves nothing.
- Have a socket you know works. A faulty power strip or an old socket muddles the diagnosis.
- Look into the charging port against the light. If the bottom looks shallow or has a greyish block in it, you have already found the problem.
- Do not use metal objects, needles, paperclips or water to clean the port. Scratching the contacts turns a cheap problem into a parts replacement.
Solutions, in the order to try them
1Carefully clean the charging port
This is the first fix because it solves more cases than all the others combined. Pockets push lint into the port and, over time, the connector itself packs it into a hard block at the bottom. The cable still goes in, but it does not reach the contacts. The classic symptom is having to hold the cable at an angle for it to charge.
- Switch the iPhone off before touching the port.
- Shine a torch into the port and compare it with another device if you have one.
- Use a wooden toothpick with a blunted tip and gently scrape the walls and the bottom, always working outwards.
- Pull the lint out a bit at a time and shake the phone with the port facing down between passes.
- If you have compressed air made for electronics, use short bursts with the can held upright, never tilted.
- Turn the phone on and try the cable: if it now seats deeper and clicks firmly, you have fixed it.
2Swap the cable for one you know works
The cable is the part that fails most, because it bends hundreds of times at the same spot. The internal wires break long before the outer sheath shows anything, so an apparently perfect cable can be dead. Change it for one you have seen working on another device, not for a random one from the drawer.
- Plug the suspect cable into another compatible device: if it will not charge there either, the cable is the culprit.
- Test your iPhone with a borrowed cable that you know works.
- Inspect both connectors against the light: darkened, bent or greenish pins mean the cable is finished.
- Squeeze and twist the cable near the connector while it is plugged in: if the charging bolt flickers, a wire is broken in there.
- Prefer Apple-certified cables. Very cheap cables often charge badly and can stop working after a system update.
3Change the power supply and the socket
The power supply and the socket are two separate variables and both need testing. USB ports on computers, keyboards, televisions and car chargers deliver far less current than a wall adapter, and with the phone in use charging can be so slow that it looks like nothing is happening. A power supply with an internal fault is also common and shows nothing from the outside.
- Plug the iPhone into a wall adapter, not a computer or television USB port.
- Test the same adapter in another socket in the house, preferably straight into the wall with no power strip.
- If you have a second adapter, test with it while keeping the same cable, so you change one variable at a time.
- With the phone connected, leave it alone with the screen off for ten minutes and see whether the percentage rose.
- If you are using a car charger, test on an ordinary socket: many light up without delivering any current.
4Force the iPhone to restart
If the screen is dark and nothing reacts, the phone may be frozen rather than flat. A forced restart acts at the hardware level and deletes nothing. It is worth doing with the cable connected, so the phone comes back already taking a charge.
- Leave the iPhone plugged in for the whole procedure.
- Press and quickly release the volume up button.
- Press and quickly release the volume down button.
- Hold the side button until the Apple logo appears, which can take up to thirty seconds. Do not let go early.
- On older models with a home button, the combination is holding the home button together with the side or top button until the logo appears.
- If the logo will not appear at all, move to Solution 5 before concluding anything.
5Leave it on the charger for thirty minutes without touching it
An iPhone that ran completely flat needs to build up a minimum of energy before it can even light the screen, and that takes time. During that period it looks dead, which makes many people give up too early and keep changing cables, preventing the charge from ever starting. Leave it alone and resist testing every minute.
- Connect it with a cable and wall adapter you already validated in the previous solutions.
- Leave the phone untouched for at least thirty minutes, without unplugging and without pressing buttons.
- By the end of that time the battery symbol with the bolt should appear, or the phone should start on its own.
- If nothing showed up, touch the back of the phone: if it is warm, it is taking power and the problem is the screen.
- If it stays completely cold and lifeless after an hour on the charger, a repair centre is the next step.
6Test with wireless charging to isolate the port
This is the most elegant test in the guide. If the phone charges on a wireless pad but not through the cable, the battery and the system are proven fine and the problem is in the charging port or the cable. If it will not charge wirelessly either, the problem is deeper, in the battery or the board. It is worth borrowing a pad if you have to.
- Take the case off, especially if it is thick or contains a metal plate, a card or magnets.
- Place the phone centred on the pad and wait a few seconds for confirmation on screen.
- If it charged wirelessly, go back and redo Solution 1 more thoroughly: it is almost always a dirty port.
- If it charged neither way, note that result to tell the repair centre.
- Only models that support wireless charging work for this test; older ones need to be assessed another way.
7Check Battery Health and optimised charging
It only makes sense to look at the battery after ruling out the cable, the power supply and the port. Maximum Capacity shows how much the battery holds today compared with when it was new, and low values explain short runtime and sudden shutdowns, but rarely explain a phone that will not charge at all. This screen also explains two normal behaviours people mistake for faults.
- Open Settings, go to Battery and then Battery Health and Charging.
- Look at Maximum Capacity. Values well below eighty per cent mean a battery at the end of its life.
- If a service recommended message appears, a battery replacement is the way forward and should be done by an authorised centre.
- On the same screen, look at Optimised Charging: it holds the charge near eighty per cent and completes it close to the time you usually wake. That is normal.
- Some models offer an option to cap charging at eighty per cent. If it is on, the phone will never reach one hundred per cent, and that is not a fault.
- If charging stops by itself and the phone is hot, that is the temperature protection at work: take the case off, move it out of the sun and let it cool.
8Update the system and, if nothing worked, prepare for the repair centre
Charge management bugs have been fixed by updates before, so it is worth making sure the phone is up to date before spending on a repair. If nothing works even then, arriving at the repair centre with the tests already done saves time and stops them replacing the wrong part.
- With the phone on, open Settings, go to General and Software Update, and install anything pending.
- Make a backup before any repair, to the cloud or to a computer, because repairs can require erasing the device.
- Note down the test results: worked with another cable, with another adapter, on a wireless pad, got warm on the charger.
- Check whether the device is still under warranty before going to an unauthorised repair shop.
- If it has been in contact with water, say so. Corrosion on the port contacts is common and changes the repair completely.
Applies to
| System | Status |
|---|---|
| iPhone on iOS 16 to 18 | Confirmed |
| iPhone on iOS 15 and earlier | Confirmed |
| iPad | Port cleaning and the cable and adapter tests apply the same; an iPad needs a stronger adapter and charges very slowly from a computer USB port |
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 30, 2026 · We review this guide whenever the manufacturer changes the process.