Your charger or battery has likely failed, or the charging port is blocked
When a computer won't charge, the problem is almost always one of three things: the power adapter has stopped working, the battery itself has worn out, or the charging port is dirty or damaged. Your computer can't tell the difference between these problems — it just stops charging. The good news is that you can test each one yourself without opening the machine or buying anything.
The charging system is straightforward: electricity flows from the wall outlet through the power adapter, into the charging port on your computer, and then to the battery. If the battery is full, charging stops automatically. If any part of that chain breaks, nothing charges. Most people assume the battery is dead, but the adapter fails more often.
Key Takeaways
- Power adapters fail more often than batteries, and a dead adapter looks identical to a dead battery from the outside.
- The charging port can stop working if it gets dirty, bent, or loose inside the computer — cleaning it with a dry cloth often fixes the problem.
- You can test whether the adapter works by looking for a light on the adapter itself or by borrowing a charger from an identical computer model.
- If the battery won't charge even with a working adapter, the battery has reached the end of its life and needs replacement.
- Leaving a computer plugged in constantly after the battery is full does not damage modern batteries, but heat from the charger can shorten battery life over years.
Check the charging port for dirt or loose connections
The charging port is where the adapter plug connects to your computer. Over time, dust, lint, and debris collect inside it. This buildup blocks the electrical connection, and the computer won't charge even though the adapter is working fine.
Unplug the adapter from your computer. Look into the charging port with a flashlight — you are looking for visible dust, lint, or corrosion. If you see buildup, use a dry cotton swab or a dry soft-bristled toothbrush to gently clean inside the port. Do not use water or liquid cleaners. Plug the adapter back in and check whether the charging light appears (if your adapter has one).
If the port looks clean but the plug feels loose when you insert it, the port may be damaged inside. Gently wiggle the adapter plug while it is connected — if you have to hold it at an angle for the computer to charge, the port is bent and will need professional repair or replacement.
Test the power adapter by looking for a charging light
Most power adapters have a small light on the adapter itself or on the cable near the plug. When you connect the adapter to power, this light should turn on. If the light does not appear, the adapter is not receiving power from the wall outlet.
First, try plugging the adapter into a different wall outlet in another room. Outlets fail sometimes, and a different outlet will tell you whether the problem is the outlet or the adapter. If the light still does not appear, the adapter has failed and needs replacement.
If your adapter has no light, or if you are not sure whether it is working, borrow a charger from someone with the exact same computer model. The model number is usually printed on the bottom of your computer or in the system settings. Plug in the borrowed charger and wait five minutes — if your computer starts charging, your original adapter is dead. If it still does not charge, the problem is your computer itself, not the adapter.
Understand what happens when the battery wears out
Batteries have a limited lifespan. Every time a battery charges and discharges, it loses a tiny amount of capacity. After 300 to 1,000 full charge cycles (depending on the battery type and how you use it), the battery can no longer hold a charge. At that point, your computer will run only while plugged in.
You can check your battery's health on Windows by opening Command Prompt as administrator, typing powercfg /batteryreport, and pressing Enter. This creates a file showing how much capacity your battery has left compared to when it was new. On Mac, hold Option and click the battery icon in the top right — it will show you the battery condition. If it says "Service Recommended" or shows capacity below 80 percent, the battery is aging.
If the battery is worn out and a working adapter charges the computer while it is plugged in, the battery itself needs replacement. This is normal wear and tear, not a sign that you did anything wrong. Batteries are designed to be replaced.
Why leaving your computer plugged in does not ruin the battery
Modern computers stop charging once the battery reaches 100 percent. The charger then supplies power directly to the computer, and the battery sits idle. This is not harmful — the battery is not being charged or discharged, so it is not aging.
However, heat shortens battery life. If your computer runs hot while plugged in, or if the charger itself gets warm, that heat can degrade the battery over months or years. This is why gaming laptops and computers used for video editing often have shorter battery lives — they generate more heat. If you use your computer plugged in constantly, make sure the vents are clear and the computer has room for air to flow around it.
Some newer laptops have a setting to stop charging at 80 percent when plugged in for long periods. This reduces heat and extends battery life if you rarely unplug. Check your power settings or battery settings in System Preferences (Mac) or Settings (Windows) to see whether this option is available.
What to do if the adapter and port are fine but charging still does not work
If you have tested the adapter with a borrowed charger and it works, and the charging port is clean and not loose, then the problem is inside your computer. The charging circuit — the components that manage power flow from the adapter to the battery — may have failed. This requires professional repair.
Before you take it to a technician, try one more thing: shut down your computer completely, unplug the adapter, and leave it unplugged for 30 seconds. Then plug it back in and turn the computer on. Sometimes the charging circuit gets stuck in a state where it stops accepting power, and a full power cycle resets it.
If charging still does not work after that, contact the computer manufacturer's support line or visit a repair shop. Provide them with the adapter model number and tell them you have already tested the adapter and port. This information will help them diagnose the problem faster.
Frequently Asked Questions
Can I use a different brand charger if mine stops working?
Only if it has the same voltage and connector type as your original charger. Using the wrong voltage can damage your computer or battery. Check the voltage printed on both adapters — they must match exactly. When in doubt, use the original charger or buy a replacement from the computer manufacturer.
Does my computer charge faster if I use it while plugged in?
No. The charging speed is determined by the power adapter and the charging circuit inside your computer, not by whether you are using it. However, using the computer while it charges generates heat, which can slow charging slightly and reduce battery lifespan over time.
What if the charging light comes on but the battery percentage does not increase?
The battery may be completely dead and needs time to charge before it will turn on. Leave it plugged in for at least 30 minutes without using it. If the percentage still does not increase after an hour, the battery has failed and needs replacement.
Is it bad to leave my computer plugged in overnight?
No. Once the battery reaches 100 percent, the charger stops sending power to it. The computer draws power directly from the adapter instead. The only concern is heat — if your computer gets warm while plugged in, make sure it has good ventilation to prevent long-term battery damage.
Why does my computer show it is charging but the battery percentage goes down?
The power adapter is not supplying enough power for both the computer and charging at the same time. This happens when you use a lower-wattage adapter than the original, or when the computer is running demanding tasks like video editing or gaming. Plug in the original adapter and close unnecessary programs to let the battery charge.