Probably Not Broken: Phone Not Charging or Charging Slow, the Cable, the Port and the Lint
A phone that will not charge is usually not a broken phone. In the order the manufacturers themselves put them, the things to check are the cable, the plug, the socket, and whether the port is blocked with pocket lint. Samsung says outright that debris in the port will stop charging on purpose, as a safety measure. Work through those before you pay anyone anything.
What is happening?
- Nothing at all when you plug inSwap the cable first, then the plug. The three swaps
- It charges only if you hold the cable at an angleThat is the port or the cable, and one is cheap. How to tell
- It charges, but painfully slowlyUsually the plug, not the phone. Why
- It says "slow charging" on screenYour phone is telling you the power supply is weak. What to change
- It stops at 80 per centNot a fault. Apple designed that. The setting
- You have an iPhoneWhat Apple says to check
- You have a Samsung or another AndroidGoogle's and Samsung's own steps
Everything before the buying suggestion at the end costs nothing to try.
- Phone not charging? Start with three swaps
- The charging port: blocked, or damaged?
- Why is my charger not working: the cable and the plug
- iPhone not charging: what Apple says to check
- Samsung phone not charging: the makers' own steps
- Why is my phone charging slow?
- Why is my phone not charging past 80 per cent?
- When the charging port really is damaged
- Quick answers
Phone not charging? Start with three swaps
Before anything else, change one thing at a time: a different cable, a different plug, a different socket. Most phones that are not charging are fixed by one of those three, and each takes a minute.
Do them in that order, because that is roughly the order of how often each fails. Cables are thin, they get bent at the connector, they live in bags and under chair wheels, and they die from the inside where you cannot see it. Plugs fail less often. Wall sockets and extension leads fail least often of all, but they do fail.
Some specifics that make the test actually worth doing:
- Use a cable you know works, not another one from the same drawer that has had the same life.
- Plug into the mains, not a laptop or a car. A USB port on an old laptop can deliver so little power that a modern phone barely holds its charge.
- Give it a minute. A phone that is completely flat can sit there looking dead for a while before it shows anything.
- Then restart the phone. Google’s first instruction for an Android that will not charge is to hold the power button for five to seven seconds, which restarts it.
If a different cable fixes it, you have your answer and it cost you a cable. If nothing changes across all three swaps, carry on to the port.
The charging port: blocked, or damaged?
If your phone only charges when you hold the cable at a certain angle, or the cable feels loose in the socket, the problem is the port or the connector. The good news is that the most common cause is compacted pocket lint, not damage.
This is not folklore. Samsung says that if dust or debris is stuck in the charging port or the cable connector, charging may be blocked for safety, and it tells you to remove the debris with a soft brush. Google’s guidance for Android says to check that there is nothing in the port of your phone, like dust or lint.
The same thing lies behind the searches for an iPhone charger jack not working or an iPhone charger slot not working: on an iPhone the “jack” and the “slot” people mean is this one port, and nine times out of ten it is blocked rather than broken.
A phone lives in a pocket. Every time it goes in, a little more fluff goes into the port with it, and every time you plug the cable in you compress that fluff into a solid pad at the bottom. Eventually the connector can no longer seat fully, and a connector that is not fully seated does not charge reliably.
How to clear it safely:
- Turn the phone off first.
- Look into the port with a bright light. If you can see grey felt at the bottom, that is your problem.
- Use something wooden or plastic, such as a toothpick, and scrape gently towards the opening. Samsung suggests a soft brush.
- Never use a metal pin or a paperclip. The contacts are right there, and shorting them is how a cheap fix becomes an expensive one.
- Avoid canned air blasted straight in, which tends to pack the lint tighter rather than lift it out.
If the port is clean and the cable still wobbles in it, or if you can see bent or discoloured contacts, that is genuine damage and it needs a repair rather than a purchase.
Why is my charger not working: the cable and the plug
A charger has two halves that fail differently. The cable fails mechanically, usually at the connector where it flexes. The plug fails by being too weak for the phone rather than by breaking, which is why it so often looks fine and still leaves you at 40 per cent in the morning.
Samsung puts this plainly in its own troubleshooting: low quality or non-approved chargers and cables may cause slow charging or intermittent disconnection. Intermittent disconnection is the polite name for the charge that keeps starting and stopping all night.
Three things separate a cable that works from one that does not:
- The wattage it is built for. A cable rated for a low power delivery will not carry a fast charge no matter what plug you attach.
- Strain relief at the connector. The moulded section where cable meets plug is what stops the wires inside from breaking. Cheap cables have almost none.
- Whether it is a charging cable at all. Some very thin cables that came with an accessory are built for data or for trickle power only.
On the plug side, the number that matters is watts. A phone that supports fast charging needs a plug that can supply it, and an old 5W plug from a previous phone will charge a modern handset at a crawl. Our guide to USB-C, explained goes through what the ratings mean and why two identical-looking cables behave differently.
iPhone not charging: what Apple says to check
If your iPhone is not charging, the sequence is the same as any phone: cable, plug, socket, port. What is worth knowing separately is Apple’s charging behaviour, because a good deal of what gets reported as “my iPhone is not charging” turns out to be the battery features working as intended.
Two of those are covered below, in the 80 per cent section, and they account for a surprising share of the worry.
The genuinely iPhone-specific things to check:
- The Lightning or USB-C port collects lint faster than you would think, because the opening is shallow and the phone spends its life in a pocket.
- A case can hold the connector just far enough out to stop it seating. Take the case off and try again before you conclude anything.
- Force restart the phone if it is showing nothing at all. On recent models that is volume up, volume down, then hold the side button until the Apple logo appears.
- A “liquid detected” warning stops charging on purpose. That is a safety feature, not a fault, and the phone needs to dry before it will charge over the cable.
If you have run through all of that and it still will not take a charge on a cable you have proved works, that is the point to book a repair rather than keep buying accessories.
Samsung phone not charging: Google’s and Samsung’s own steps
Google and Samsung both publish troubleshooting for this, and it is worth reading what they put first, because it is not what most articles put first.
Google’s order for an Android that will not charge or turn on: hold the power button for five to seven seconds to restart the phone; then check that the cable is securely connected to both the adapter and the phone, and that there is nothing in the port like dust or lint; then plug in with a cable, charger and socket you know work, and wait a minute.
Samsung’s order for a Galaxy that is not charging is longer and starts somewhere unexpected. It asks you to check the estimated charging time in Settings, then Battery. Then it tells you to stop using the phone while it charges, because games, video and browsing raise the temperature and slow the charge. Then to check your fast charging setting is on. Then temperature, because charging is limited if the phone or the room is too hot or too cold. Then the charger and cable. Then the port and debris. Then a reboot with power and volume down. Then the diagnostics in the Samsung Members app.
Two things stand out in that list. The first is how early “you are using the phone while it charges” appears, which is a real cause of slow charging that people rarely suspect. The second is temperature: a phone charging on a sunny windowsill or under a pillow will deliberately slow down or stop, and there is nothing wrong with it.
If your phone is a Samsung, the Samsung Members app is genuinely useful here, because it will test the battery and the cable charging for you and tell you which one is failing.
Why is my phone charging slow, and what “slow charging” on screen means
If your phone charges but takes forever, the plug is the first suspect, not the phone. If your phone actually displays the words “slow charging”, it is telling you it has detected a power supply that cannot give it what it wants.
The usual causes, most common first:
- An underpowered plug. An old low-wattage adapter will charge a modern phone, just very slowly.
- A cable that cannot carry the power, even with the right plug on the end of it.
- Charging from a laptop, a car socket or a plug socket in a hotel lamp, all of which can be far weaker than a mains charger.
- Using the phone while it charges. Samsung names this explicitly: games, video and browsing raise the temperature and slow the charge.
- Heat. Samsung says charging may be limited if the device or the surrounding environment is too hot or too cold. A phone on a car dashboard in summer will barely charge, by design. A phone overheating while charging is the same story from the other end: the heat is the cause of the slowdown, not a separate fault.
- A part-blocked port, which can leave a connection good enough for a trickle and not for a fast charge.
The quickest way to separate plug from phone: charge it from a plug you know is powerful, with a cable you know is good, and leave it alone for half an hour. If it gains a decent amount, your hardware was the problem. If it barely moves, look at the port and the battery.
Why is my phone not charging past 80 per cent? That one is not a fault
If your iPhone will not charge past 80 per cent, that is almost certainly Apple’s battery protection doing its job, not something broken. Apple has two separate features here and it is worth knowing which one you are looking at.
Optimised Battery Charging is, in Apple’s words, “designed to reduce the wear on your battery and improve its lifespan by reducing the time your iPhone spends fully charged”. Apple says that when it is enabled, “your iPhone will delay charging past 80 per cent in certain situations”, using on-device learning to work out your routine so it finishes charging around the time you normally unplug. It is on by default. If you need a full battery sooner, touch and hold the Lock Screen notification and tap Charge Now.
Charge Limit is the newer one and it is a hard ceiling you choose. On iPhone 15 and later, in Settings, then Battery, then Charging, you can pick a limit between 80 and 100 per cent in 5 per cent steps. Apple says the phone “will charge to within a few percentage points of your chosen limit and then stop charging”, and will resume if the level drops more than 5 per cent. iOS may also suggest a limit on its own: Apple’s example is a notice reading “Based on your iPhone habits, a charge limit of 95% is recommended to help preserve your battery”. On iPhone 14 and earlier the setting lives in Settings, then Battery, then Battery Health and Charging.
One detail that catches people out: Apple says that if your Charge Limit is set below 100 per cent, the iPhone “will occasionally charge to 100 per cent to maintain accurate battery state-of-charge estimates”. So an occasional full charge on a limited phone is also normal.
Android phones from several makers have their own version of this, usually under battery protection or battery care settings, and it works the same way. If your phone parks itself at 80 or 85 per cent overnight, look for that setting before you assume the battery is failing.
When the charging port really is damaged, and what a repair is worth
You have earned the right to suspect the phone once a known-good cable, in a known-good plug, in a known-good socket, with a clean port and the case off, still will not charge it.
Signs that point at the phone rather than the accessories:
- The port is visibly damaged, with bent, missing or discoloured contacts.
- It charges only at one specific angle, on every cable you try.
- It gets noticeably hot at the port while charging.
- The battery percentage jumps around, or the phone shuts down well above zero.
- It has taken a drop or a soaking recently.
A charging port replacement is one of the cheaper phone repairs, and considerably cheaper than a phone. A battery replacement is also usually worth it on a handset you otherwise like. What is rarely worth it is buying a third and fourth cable in the hope that the next one is different.
If the phone is old enough that you were thinking about replacing it anyway, our iPhone buying guide and the iPhone 18 release timing are the two things worth reading before you spend on a repair.
Quick answers
In order of likelihood: the cable has failed internally, the plug is too weak or dead, the socket is off, or the charging port is packed with pocket lint. Change one thing at a time, starting with the cable. On a Samsung, debris in the port blocks charging deliberately, as a safety measure.
Look in with a bright light. Grey felt at the bottom is lint and it can be cleared. Bent, missing or discoloured contacts are damage. A practical test: if the phone charges only when you hold the cable at a particular angle, and it does that with more than one cable you have proved works, the port is the problem.
Turn the phone off, look inside with a light, and gently work the debris out with something wooden or plastic such as a toothpick, scraping towards the opening. Samsung suggests a soft brush. Never use a metal pin, because the contacts are exposed, and avoid blasting canned air straight in, which packs the lint tighter.
Try a cable and plug you know work, take the case off in case it is holding the connector out, check the port for lint, and force restart the phone. If you see a liquid-detected warning, charging is being blocked on purpose until the port dries. If it charges to 80 per cent and stops, that is a battery feature rather than a fault.
On an iPhone this is battery protection. Optimised Battery Charging delays charging past 80 per cent in certain situations to reduce wear, and on iPhone 15 and later a Charge Limit lets you set a ceiling between 80 and 100 per cent. Touch and hold the Lock Screen notification and tap Charge Now if you need a full battery sooner. Many Android phones have an equivalent battery-protection setting.
The phone has detected that the power supply cannot deliver what it expects. Nearly always that means an underpowered plug, a cable that cannot carry the current, or charging from a laptop or car socket. Swap to a mains charger rated for your phone and a cable built for that wattage.
Beyond the plug and cable, two causes people rarely suspect: using the phone while it charges, and heat. Samsung says games, video and browsing while charging raise the temperature and slow the charge, and that charging may be limited if the device or the environment is too hot or too cold.
Samsung's order is: check the estimated charging time in Settings then Battery, stop using the phone while charging, check your fast charging setting, check the temperature, check the charger and cable, check the port for debris, reboot with power and volume down, then run the diagnostics in Samsung Members. That last one will test the battery and cable charging for you.
Yes, and it is the single most common cause. The wires break inside the moulding at the connector, where the cable flexes most, long before the outside shows anything. This is why swapping in a cable you have proved works is the first test rather than the last.
Usually, yes. A port replacement is one of the cheaper phone repairs and much cheaper than a new phone. It is worth it once you have ruled out the cable, the plug, the socket and lint, because those four cost nothing to test and account for most cases.
No, it is just slow. A USB port on an older laptop delivers a fraction of what a mains charger does, so the phone may barely gain charge while you use it. If you need speed, use a mains plug rated for fast charging.
It is fine on a modern phone, and the battery features are built for exactly that. Apple's Optimised Battery Charging exists to reduce the time the phone spends sitting at 100 per cent overnight, and several Android makers have their own version. If anything, letting those features do their job is better for the battery than unplugging at 100 per cent every night.
If your charger is not working, what to replace it with
If the swap test pointed at your charger rather than your phone, these are the chargers, cables and power banks we sell that are built for the wattage modern phones actually use. You do not need the most expensive one. You need one rated for the power your phone can take, with proper strain relief where the cable meets the connector. Buying a power bank for a trip? Check the rules for taking a power bank on a plane first, because airlines limit the size. For which one to buy, see our power bank buying guide.
Sources
- Apple, About Charge Limit and Optimised Battery Charging on iPhone. The definition of Optimised Battery Charging, the delay past 80 per cent, Charge Now, the 80 to 100 per cent Charge Limit in 5 per cent steps on iPhone 15 and later, and the occasional full charge to keep estimates accurate.
- Google, Fix an Android device that won’t charge or turn on. The five to seven second power button restart, and checking the cable connection and the port for dust or lint.
- Samsung, What to do if your Samsung phone is not charging. The full order of checks, the temperature limits, the note on low quality or non-approved chargers and cables, and the soft brush for debris in the port.
Photographs are from Pexels, used under the Pexels License, which permits commercial use. Each has been cropped to fit.
