If your phone is not charging, do not assume immediately that the battery or charging port has failed. A bad cable, weak power adapter, blocked USB-C port, moisture warning, excessive heat or even a battery-protection setting can all stop or slow charging.
The quickest way to find the problem is to work from the simplest external causes towards the phone itself.
Start with the socket, charger and cable. Next, inspect the charging port, check for moisture or temperature warnings and restart the phone. Only after those checks should you start suspecting a failed port, battery or internal charging component.
Apple, Samsung and Google all recommend checking the cable, power adapter, socket and charging port early in the troubleshooting process.
Here are 17 causes to work through.
1. The charging cable has failed
Cables fail more often than many people realise.
They bend repeatedly, get pulled from connectors, sit under furniture and travel in bags or pockets. Damage can also occur internally without an obvious break in the outer insulation.
Test the cable with another device
If possible, use the same cable and adapter to charge another compatible phone or device.
Alternatively, try a known-working cable with your phone.
If the replacement cable works immediately, you have probably found the problem.
Look for physical damage
Stop using a cable if you notice:
- exposed wires;
- split insulation;
- loose connectors;
- bent contacts;
- heat around the plug;
- obvious scorching or discolouration.
Replacing a damaged cable is safer than repeatedly adjusting it until the phone starts charging.
2. The charger or power adapter is faulty
A good cable cannot compensate for a failed adapter.
Try another compatible power adapter and, ideally, another wall socket.
Do not test several unknown components together
If you change the cable, adapter and socket simultaneously, you may fix the problem without knowing which component caused it.
Instead, change one item at a time.
That simple approach makes troubleshooting much quicker.
3. The wall socket or power source is the problem
The phone itself may be completely healthy.
A faulty socket, switched-off extension lead, weak laptop USB port or poorly connected power strip can produce the same symptom as a broken phone.
Try a normal wall socket
Apple and Google both recommend testing a direct power source when investigating charging faults.
A laptop USB port may also charge significantly more slowly than a compatible wall adapter.
Therefore, use a reliable wall charger when diagnosing the problem.
4. There is dirt or lint inside the charging port
This is particularly common on phones carried in trouser pockets.
Small amounts of lint can gradually compact at the bottom of the USB-C or Lightning connector.
Eventually, the plug no longer seats correctly.
Common signs of a blocked port
- the cable does not insert as far as expected;
- charging starts and stops when the plug moves;
- the phone only charges at a particular angle;
- different cables have the same problem;
- the connector feels unusually loose.
Be careful when cleaning it
Inspect the port under good lighting.
Do not aggressively scrape internal contacts or push metal objects into the connector.
If debris is tightly packed or you are unsure how to remove it safely, a repair shop can inspect and clean the port without risking damage to the contacts.
5. Your phone has detected moisture
Modern phones may deliberately disable wired charging when they detect liquid inside or around the charging connector.
That is a protection feature, not necessarily a hardware failure.
Samsung may show a water-drop warning
Samsung says supported Galaxy devices can block charging when moisture exceeds a defined level inside the USB port.
The company advises switching the phone off and allowing it to dry completely.
iPhone can disable the connector too
Supported iPhones display a liquid-detection alert when moisture is detected in the Lightning or USB-C connector or attached accessory.
Apple warns that charging a wet connector can corrode the pins and cause permanent damage.
6. The port is still drying after liquid exposure
A charging connector can look dry externally while moisture remains around internal contacts.
Apple advises leaving an affected iPhone in a dry area with airflow and trying again after at least 30 minutes.
If the warning remains, complete drying can take considerably longer.
Avoid common drying mistakes
Apple specifically advises against:
- external heat sources;
- compressed air;
- putting objects such as cotton buds inside the connector;
- placing the phone in rice.
Drying naturally is slower, but it reduces the risk of causing additional damage.
7. The phone is too hot
Charging creates heat.
Games, video, navigation, high screen brightness and warm environments can add more heat at the same time.
To protect the battery, a phone may reduce charging speed or pause charging altogether.
Let the device cool naturally
Move the phone away from direct sunlight or another heat source.
If you are running an intensive game or application, close it and allow the handset to cool.
Apple and Samsung both document temperature as a reason charging may slow or pause.
8. The phone is too cold
Very low temperatures can also affect charging behaviour.
Battery-management systems may restrict charging until the battery returns to an acceptable temperature range.
Return it to normal room temperature
Do not use artificial heat to warm the battery rapidly.
Instead, move the phone into a normal indoor environment and give it time to stabilise.
9. Your charger does not provide enough power
A charger can technically work but still be much slower than expected.
This is particularly noticeable on newer flagship phones.
USB-C does not guarantee a particular charging speed
The shape of the connector does not tell you how much power the charger can provide.
Power output, supported charging standards and cable capability all matter.
For example, Apple recommends USB-C Power Delivery for faster wired charging on compatible iPhones.
Google similarly recommends suitable USB Power Delivery or PPS chargers for modern Pixel devices.
10. The phone says it is charging, but the battery is going down
This can happen when the phone consumes power faster than the charger supplies it.
Heavy gaming, navigation, video streaming or camera use can raise power consumption considerably.
The charger may only be slowing the battery drain
Imagine the phone is consuming 12 watts while the charging setup effectively provides less power than the device needs in that situation.
The charging symbol may appear, yet the battery percentage can still decrease.
Try locking the screen and leaving the phone unused for 15–30 minutes.
If the battery starts increasing normally, excessive usage or inadequate charging power may be the explanation.
11. Your phone deliberately stops charging at 80%
This is increasingly common and often mistaken for a fault.
Manufacturers now offer battery-protection settings designed to reduce the time lithium-ion batteries spend at very high charge levels.
iPhone 15 and later can use Charge Limit
Apple allows users to select a maximum charge level between 80% and 100% on supported iPhones.
If you have chosen an 80% limit, the phone is behaving correctly when it stops there.
Samsung Galaxy can also stop at 80%
On supported Galaxy phones, Samsung’s Maximum Battery Protection mode stops charging when the battery reaches approximately 80%.
Pixel offers an 80% limit too
Google provides a Limit to 80% charging option on supported Pixel phones.
Therefore, always check battery-protection settings before replacing hardware because a phone consistently stops around 80%.
12. Optimised or adaptive charging is delaying 100%
A phone does not always need a hard 80% limit to delay charging.
Apple, Samsung and Google also use adaptive systems designed to reduce unnecessary time spent fully charged.
The phone learns how you charge
For example, a device plugged in overnight may pause or slow around 80% and complete the final part closer to when it expects you to unplug it.
This is intended to reduce battery wear.
If charging eventually reaches 100% at the expected time, the system may be functioning normally.
13. Wireless charging is not aligned correctly
Wireless charging requires the charging coils in the phone and charger to line up closely enough to transfer power efficiently.
Poor positioning can cause slow, intermittent or failed charging.
Remove anything interfering with alignment
Try:
- repositioning the phone;
- removing an unusually thick case;
- removing metal objects or cards;
- trying a compatible charger;
- checking that the charging pad itself has power.
Magnetic charging systems such as MagSafe and Qi2 make alignment easier on compatible devices, but charger compatibility still matters.
14. A case or accessory is blocking the connector
Some cases prevent USB plugs from inserting completely.
The connection can look correct while the plug sits slightly short of the internal contacts.
Remove the case during testing
Google specifically recommends checking whether a case interferes with the charging connection or wireless charger.
If charging works normally with the case removed, the phone itself may not need any repair.
15. The phone needs a restart or software update
Charging involves software as well as hardware.
The operating system communicates with the battery-management and charging systems.
A temporary software fault can therefore produce unusual charging behaviour.
Restart before booking a repair
Apple and Google both include restarting the phone in their official charging troubleshooting.
If a normal restart is not possible, follow the manufacturer’s instructions for the relevant model.
Afterwards, install any current operating-system updates and test again.
16. The charging port is physically damaged
If several known-good cables and adapters fail, the port itself becomes more suspicious.
Signs of port damage include:
- visible bent contacts;
- corrosion;
- the connector moving excessively;
- charging only while pressure is applied;
- USB data no longer working;
- repeated connection and disconnection;
- obvious impact damage.
A port can also develop faults internally even when it looks normal from the outside.
Charging only at an angle is an important clue
If the phone consistently charges only when the cable is pushed or held in one direction, investigate the port, debris and connector before blaming the battery.
Continuing to force the plug sideways can make physical damage worse.
17. The battery or internal charging hardware has failed
Once external causes have been ruled out, the fault may be inside the phone.
Potential problems include the battery, port assembly, flex cable, charging circuitry or another board-level component.
A failed battery can show several symptoms
These may include:
- very rapid battery drain;
- unexpected shutdowns;
- poor battery-health readings;
- failure to retain charge;
- excessive heat;
- abnormal swelling.
If the battery or phone is visibly swollen, stop using it and arrange professional service rather than continuing to charge it.
Why does my phone show no charging symbol at all?
A completely flat battery may not display anything immediately after connection.
Apple recommends allowing an unresponsive device to charge for a period before trying again.
Google similarly distinguishes between a phone that will not charge and one whose screen remains blank.
Give a deeply discharged battery some time
Connect the phone to a known-working wall charger and leave it alone for around 30 minutes.
If there is still no response, try the appropriate restart procedure.
Continued failure after known-good charging equipment increases the likelihood of a hardware fault.
Why does my phone keep connecting and disconnecting from the charger?
Intermittent charging usually points towards an unstable connection.
Start with the physical connection
Check:
- cable condition;
- connector fit;
- port debris;
- port damage;
- adapter stability;
- moisture warnings.
If the problem occurs with several cables, the handset’s port deserves closer inspection.
Why is fast charging suddenly not working?
Fast charging requires the entire charging chain to support the necessary standard.
Changing just one component can reduce the charging rate.
Check the complete setup
You may need:
- a phone that supports the relevant fast-charging standard;
- a suitable power adapter;
- a cable rated for the required power;
- a stable electrical connection;
- a battery within an acceptable temperature range.
If the phone becomes too warm, it may reduce power even with a powerful charger connected.
Why does my Samsung say “Moisture detected” when it is dry?
Samsung’s moisture-detection system can occasionally continue showing a warning after the visible moisture has disappeared.
First, allow the port to dry thoroughly.
Persistent warnings need further investigation
Samsung’s current support guidance includes additional troubleshooting where the icon remains after the phone has dried.
However, repeated moisture warnings can also indicate contamination or a connector-related problem.
If the message continually returns without obvious liquid exposure, consider professional inspection.
Why does my iPhone say the accessory is not supported?
Apple says this alert can appear when:
- the charging port is dirty or damaged;
- the accessory is damaged;
- the accessory is not suitable for charging the device.
Try a direct connection first
Remove intermediate adapters or accessories and connect directly to a known-working charger.
Then test another cable and adapter if needed.
Also make sure the iPhone is running current software.
Should you clean a USB-C charging port yourself?
Basic visual inspection is sensible.
Aggressive DIY cleaning is not.
USB-C contains small internal contacts
Scraping them with metal tools can turn a simple lint problem into an expensive port repair.
If compacted debris will not come away safely, let a technician clean the connector.
This is particularly sensible when the phone still charges intermittently because the contacts may already be under mechanical stress.
Does a charging problem mean the battery needs replacing?
No.
A failed battery is only one possible cause.
Replacing the battery will not fix:
- a broken cable;
- a failed adapter;
- lint in the port;
- a damaged USB connector;
- moisture detection;
- an incompatible charger;
- a software charging limit.
Therefore, proper diagnosis should come before parts replacement.
When should you stop troubleshooting and get the phone repaired?
Simple checks make sense at home.
Continuing indefinitely does not.
Arrange professional inspection if:
- several known-good chargers fail;
- the charging port is visibly damaged;
- charging works only at an angle;
- the phone becomes abnormally hot;
- the battery is swollen;
- liquid entered the phone;
- charging repeatedly starts and stops;
- USB data no longer works;
- the phone remains completely unresponsive after extended charging.
The technician can then determine whether the fault lies with the port, battery or deeper charging circuitry.
A quick phone-not-charging checklist
First five minutes
- Try another wall socket.
- Test another known-good cable.
- Try another compatible adapter.
- Remove the phone case.
- Inspect the charging port for debris.
Next checks
- Look for moisture warnings.
- Check whether the phone feels unusually hot or cold.
- Restart the device.
- Check battery charging limits.
- Leave a completely flat phone charging for around 30 minutes.
If it still does not charge
- Test wireless charging if the phone supports it.
- Check whether USB data works.
- Look for visible port damage.
- Review battery-health information.
- Arrange professional diagnostics.
Why charging faults matter to used-phone buyers
A phone can appear completely normal during a quick marketplace inspection while hiding an intermittent charging problem.
That makes charging part of any sensible second-hand device check.
Do not simply look for the charging icon
When inspecting a used phone, check whether:
- the cable fits normally;
- charging remains stable when the phone rests untouched;
- the battery percentage actually increases;
- the port also supports normal USB behaviour;
- wireless charging works where relevant;
- the device becomes excessively hot.
An intermittent USB-C port can turn a cheap used-phone purchase into an immediate repair.
Repair shops should diagnose before replacing the port
Charging faults can look deceptively similar.
For example, lint in the connector, a worn cable and a mechanically damaged USB port can all cause intermittent charging.
Record the customer’s exact symptom
Useful questions include:
- Does the phone charge with any cable?
- Does it charge wirelessly?
- Does fast charging work?
- Does the cable need to be moved?
- Has the phone been exposed to liquid?
- Did the problem begin after a drop?
- Does a computer recognise the device over USB?
Those answers can narrow the diagnosis before the technician opens the handset.
Run diagnostics before and after repair
A charging-port repair should not end when the battery icon appears.
The rest of the phone still needs to function correctly.
Pre-repair testing establishes a baseline
Testing before repair helps identify faults that existed before the technician started work.
That can reduce disputes later.
Post-repair testing catches unintended problems
After reassembly, check relevant:
- display functions;
- touch;
- speakers;
- microphones;
- buttons;
- sensors;
- Wi-Fi;
- Bluetooth;
- USB connectivity.
A phone can charge correctly while still having another issue introduced or missed during the repair.
How MobiTEST supports phone diagnostics
MobiTEST gives professional device businesses a guided diagnostic workflow across hardware, display, sound, sensors and connectivity.
MobiCode’s current platform includes USB connectivity testing alongside Wi-Fi and Bluetooth checks.
It should not be presented as a charging-circuit analyser
That distinction matters.
MobiTEST can help verify USB connectivity and other device functions as part of the wider diagnostic process.
It does not replace electrical fault-finding on a damaged battery, charging IC or board-level circuit.
For repair teams, the benefit is a repeatable wider handset check around the actual repair.
How MobiONE helps higher-volume operations
Refurbishers and recyclers may process hundreds or thousands of phones rather than one repair at a time.
At that scale, inconsistent testing becomes expensive.
One technician’s quick check is not enough
MobiONE brings device lookup, guided diagnostics, grading and other processing stages into a centralised workflow.
For an incoming device with a possible charging fault, a business can build a consistent process around:
- identifying the device;
- recording its condition;
- checking relevant status information;
- running diagnostics;
- routing failed devices for repair;
- retesting afterwards;
- grading the final handset.
Consistency matters because missed charging faults often become returns, refunds or warranty claims.
Charging faults should influence refurbishment economics
A repairable fault is not automatically an economical repair.
Work backwards from resale value
Suppose a used phone should sell for £300 when fully working.
The device needs a charging-port repair, battery assessment and labour.
The refurbisher should consider:
- purchase price;
- parts;
- labour;
- testing;
- selling fees;
- warranty exposure;
- expected resale price.
If those costs remove the margin, routing the handset differently may make more commercial sense.
Commercial takeaway
“Phone not charging” is a symptom, not a diagnosis.
The fault might cost nothing to fix if the problem is a charging setting or an incompatible cable. Alternatively, the handset may need a new port, battery or internal repair.
For consumers
Start with the external components.
Test another cable, adapter and power source. Inspect the connector, check for moisture and temperature warnings, restart the phone and review battery-protection settings.
Do not replace hardware until the simpler causes have been ruled out.
For repairers and device businesses
Charging complaints need a repeatable diagnostic process.
Record the original symptom, check the device before repair and retest it afterwards.
MobiTEST supports structured functional and connectivity diagnostics, while MobiONE helps higher-volume businesses standardise the wider device-processing workflow.
The objective is simple: find the actual fault before replacing parts, and prove the phone works before it goes back to the customer or into resale stock.
A practical example: a phone that “needs a new charging port”
A customer brings a two-year-old Android phone into a repair shop.
They explain that the phone only charges when the USB-C cable is pushed firmly upwards.
The customer assumes the charging port needs replacing.
The technician starts with the simple checks
A known-good cable produces the same symptom.
Another charger does not change the behaviour either.
However, inspection under good lighting shows a layer of compacted pocket lint at the bottom of the USB-C port.
The port is cleaned safely
Once the contamination is removed, the connector seats fully again.
Charging becomes stable without applying pressure to the cable.
The device then goes through functional checks
USB connectivity, speakers, microphones, touchscreen, cameras, Wi-Fi and Bluetooth all operate normally.
The customer does not need a replacement port after all.
The example illustrates why diagnosis matters.
Replacing the port immediately would have created unnecessary cost, labour and repair risk when the actual problem was contamination.
Frequently asked questions
Common charging problems
Why is my phone not charging when plugged in?
Common causes include a faulty cable or adapter, a blocked or damaged charging port, moisture detection, incompatible charging equipment, temperature protection, software problems or a battery or internal hardware fault.
Why does my phone only charge at an angle?
The connector may not be seating correctly because of compacted debris, cable damage or mechanical wear in the charging port. Try a known-good cable and inspect the port before assuming the battery has failed.
Why does my phone say charging but the percentage goes down?
The phone may be consuming power faster than the charger supplies it. Heavy games, video, navigation, high temperatures or an underpowered charger can all cause this. Lock the phone and test with an appropriate wall charger.
Why has my phone stopped charging at 80%?
It may be intentional battery protection rather than a fault. Supported iPhones, Samsung Galaxy phones and Google Pixels can all limit or delay charging around 80% to reduce long-term battery wear.
iPhone, Samsung and Android charging questions
Why won’t my iPhone charge?
Apple recommends checking the cable, adapter, wall socket and charging port, restarting the phone and allowing a deeply discharged battery time to charge. Moisture detection, temperature and Charge Limit settings can also affect charging.
Why won’t my Samsung phone charge?
Samsung lists the battery, cable, adapter, wireless charger, charging port, moisture detection and device temperature among the possible causes. Battery Protection can also deliberately stop charging around 80% on supported Galaxy devices.
Can moisture stop a phone from charging?
Yes. Supported iPhone and Samsung devices can disable wired charging when liquid is detected around the charging connector. This protects the contacts from damage and corrosion while the port dries.
Does a phone that will not charge always need a new battery?
No. Cable faults, chargers, port contamination, moisture warnings, temperature, charging limits and port damage can all cause similar symptoms. The phone should be diagnosed before replacing the battery.
References and further reading
- Apple Support — If your iPhone won’t charge
- Apple Support — About iPhone charging speeds
- Apple Support — Charge Limit and Optimised Battery Charging
- Apple Support — Liquid detection in the iPhone charging connector
- Samsung Support — What to do if your Samsung phone is not charging
- Samsung Support — Moisture detected / water-drop charging warning
- Samsung Support — Galaxy Battery Protection
- Google Android Help — Fix an Android device that won’t charge or turn on
- Google Pixel Help — Fix a Pixel phone that won’t charge or turn on
- Google Pixel Help — Charging optimisation and 80% charge limit
- MobiCode — MobiTEST professional diagnostics
- MobiCode — MobiONE device processing