The short answer
Check the port for lint first, because compacted pocket debris is the most common cause and it looks nothing like a fault. Then confirm the charger is powerful enough, since a tablet on a phone charger may draw less power than it uses. A tablet that has been flat for weeks can take an hour before it shows any sign of life.
Tablets have large batteries and modest charging circuits, so they are slower to charge than phones and more sensitive to being underpowered. That combination produces two distinct complaints, not charging at all and charging far too slowly, with overlapping causes.
Cause 1: the port is full of lint
A USB-C or Lightning port collects pocket and bag debris, which compacts into a firm plug at the bottom. The cable then cannot seat fully, and the connection is intermittent or absent. The tell is a cable that feels shallow, wobbles, or only charges when held at an angle.
Power the tablet off
Do not clean a port with the device powered on.
Look inside with a light
A torch and a magnifier reveal a surprising amount. What looks like an empty port is usually not.
Use a wooden or plastic toothpick
Scrape gently along the sides and lift material out. Avoid metal, which can short contacts or damage the connector.
Work around the central tongue carefully
In a USB-C port there is a delicate contact strip in the middle. Do not press on it or lever against it.
Finish with a short burst of air
Then test the cable for a firm, deep click.
Cause 2: the charger is too small
Tablets typically want 18 to 45W. On a 5W phone charger, a large tablet may charge at a crawl or, if the screen is on, drain while plugged in. That is not a fault, it is arithmetic.
Use the charger that came with the tablet, or one rated at or above it with the right protocol. USB Power Delivery is the standard most tablets use, and a charger without it may fall back to the slowest mode even if it is rated for high wattage.
Cables matter as much as chargers. A USB-C cable rated only for 60W data-free charging is fine, but a cheap or damaged cable is a very common cause of slow charging. Swap it before assuming anything else.
A tablet with the screen on at full brightness playing video can consume most of what a mid-range charger supplies. If the percentage climbs while asleep and stalls while in use, the charger is adequate for standby and not for active use. That is normal for smaller chargers.
Cause 3: deep discharge
A tablet left flat for weeks enters a protective state. When you plug it in, the charging circuit trickles power at a very low rate until the cell reaches a safe voltage, and during that period the screen shows nothing at all.
Leave it connected to a proper charger, not a computer port, for at least an hour before concluding it is dead. Two hours is not unreasonable for a large tablet that has been flat for months. Then attempt a forced restart, which on most tablets is holding power and volume down for 10 to 20 seconds.
Cause 4: the cable or the brick, not the tablet
Test systematically rather than swapping one thing:
- Known-good charger with your cable.
- Your charger with a known-good cable.
- Both known-good together.
- The same charger and cable on a different device, which confirms they work at all.
Cables fail internally at the strain points near the connectors, often with no visible damage. A cable that works in one orientation and not another is failing, not fixed.
Cause 5: heat and cold
Tablets refuse to charge outside a safe temperature range, typically about 0 to 35 degrees Celsius. A tablet left in a car in summer or brought in from a freezing car will not charge until it returns to a normal temperature, sometimes without any explanatory message. Give it half an hour indoors before troubleshooting further.
Cause 6: software
- Force restart. A hung system can leave the charging indicator stuck. This is quick and resolves more cases than people expect.
- Check for updates once it is charging, since charging management is firmware-controlled and bugs do occur.
- Safe mode on Android tablets, to rule out an app holding the processor busy enough to outpace the charger.
- Charge limits. Some tablets, particularly those designed to stay plugged in, have a setting that stops charging at 80 percent to preserve the battery. A tablet stuck at 80 is often working exactly as configured.
If the tablet is warm in one specific area, the back is bulging, or the screen has lifted slightly at an edge, stop charging it. A swollen battery is a safety issue and needs professional replacement rather than further troubleshooting.
Cause 7: the port or battery itself
If the cable feels loose after cleaning, the port’s solder joints may have cracked from cable strain. This is a common repair and usually inexpensive, since the charging port is a replaceable module on many tablets.
A battery at the end of its life shows different symptoms: it charges but drops rapidly, shuts down at 20 or 30 percent, or refuses to hold anything above a low percentage. Battery health information is available in settings on many tablets, and a replacement is far cheaper than a new device on a tablet that is otherwise fine.
Why does my tablet charge so slowly?
Usually an underpowered charger or a poor cable. Tablets have large batteries and need 18W or more to charge at a sensible pace. A 5W phone charger will take most of a day.
Can I charge a tablet from a laptop USB port?
It will trickle, and on a large tablet in use it may not keep up with consumption at all. Use a mains charger for real charging.
How long should I leave a completely dead tablet charging?
At least an hour before concluding anything, and up to two for a large tablet that has been flat for a long time. The protective trickle stage shows no screen activity.
Is it safe to clean the charging port myself?
Yes with a wooden or plastic toothpick and the device powered off. Avoid metal tools and do not press on the central contact strip in a USB-C port.
Why does my tablet say charging but the percentage does not move?
The charger is supplying less than the tablet is consuming. Turn the screen off, or use a higher-wattage charger, and the percentage will begin to climb.
The order
Clean the port, then test charger and cable separately against known-good ones. Use a charger rated for the tablet rather than the nearest one to hand. Leave a flat tablet charging for at least an hour before judging it. Force restart. Check temperature and charge limits. Only then consider the port or the battery, both of which are repairable and worth pricing before replacing the tablet.
