Few laptop faults are as frustrating as plugging in and watching the battery percentage refuse to move. The cause can be anything from a worn cable to a failed chip on the motherboard, and the repair cost varies just as widely. A few simple checks will usually tell you which end of that range you are dealing with, before you buy a new charger you might not need.
First, is it really not charging?
Some laptops deliberately stop charging, and it looks exactly like a fault:
- Battery care modes. Many manufacturers include a setting that stops charging at around 80% to extend battery life, such as Lenovo’s Conservation Mode in Vantage, Dell’s Power Manager settings, ASUS Battery Health Charging in MyASUS, and similar options from HP and others. If your battery sits at exactly 60% or 80% while plugged in, check this first.
- Temperature. Batteries won’t charge when they are too hot or too cold. A laptop that has been in a cold car, or is working hard on a hot day, may pause charging until it settles.
- Full or nearly full. Some laptops won’t top up from 95% to 100% straight away, to reduce wear.
Check the charger and cable
The charger is the cheapest part to replace, so rule it out properly:
- Look at the whole cable, including where it enters the brick and the plug, for kinks, fraying or melted plastic.
- If the charger has a light, check it stays on steadily when plugged into the wall.
- Try a different wall socket, without an extension lead.
- If you can, test with a known-good charger of the correct type and wattage.
Dell and HP chargers with a round barrel plug have a thin centre pin that tells the laptop what kind of charger is connected. If that signal is lost, the laptop may run from the charger but refuse to charge the battery. On Dell laptops this often shows as a message at start-up saying the AC power adapter type cannot be determined. That can be the charger or the laptop’s socket.
USB-C charging has its own quirks
On USB-C laptops, the charger, the cable and the port all have to support the right power level:
- Not every USB-C port on a laptop accepts charging. Check the markings or the manual for the charging port.
- A phone charger or a low-wattage cable may be too weak. Windows often shows a “slow charger” warning, and the battery may drain even while plugged in during heavy use.
- Try another USB-C cable rated for the laptop’s wattage before blaming the laptop.
Signs the charging socket is the problem
The socket on the laptop takes strain every time the plug goes in and out, and every time the cable is tugged. Typical signs of a worn or broken power jack or USB-C port are:
- the charging light flickers when you move the plug;
- you have to hold the plug at an angle to get it to charge;
- the plug feels loose, or the socket looks pushed in, bent or scorched;
- a USB-C port charges with some cables and not others.
Keep using a loose socket and it can damage the board around it, so it is worth getting looked at early. Our power jack and charging port repair page explains what is involved.
Check the battery itself
Sometimes the charger and socket are fine and the battery is simply worn out. Windows can produce a detailed battery report: open Command Prompt, type powercfg /batteryreport and press Enter, then open the battery-report.html file it saves. Compare the design capacity with the full charge capacity. If the battery now holds a small fraction of its original capacity, or the laptop dies suddenly at 20 or 30 percent, a battery replacement is likely the fix.
One important warning: if the case, touchpad or keyboard is being pushed up, the battery may be swelling. Stop using and charging the laptop, keep it away from anything flammable, and get it checked. Don’t try to press the case back down.
When it is the motherboard
If a known-good charger, a solid socket and a healthy battery still don’t produce any charging, the fault is usually in the charging circuit on the motherboard. Clues include:
- the laptop runs on the charger but the battery never charges, even with a new battery;
- it works only on the battery, or only on the charger;
- no charging light at all, with any charger;
- the problem started after a spill, a drop or a power surge.
These faults are often a single failed component, such as a charging controller chip, a fuse or a protection part, rather than a ruined board. Repairing at component level, rather than replacing the whole board, is usually far more economical. See our motherboard repair service for how we diagnose and fix them.
Get your laptop charging again
Bring the laptop and its charger to our workshop at 80 Willow Walk, Unit 1, London SE1 5SY. We’re open Monday to Saturday, 9am to 6pm, and you can walk in without an appointment. You can also call 020 7394 2525, email support@gantonit.co.uk, or book a repair online. We’ll test the charger, socket, battery and board, and tell you what the fault is and what it costs before any work starts.
