Modern laptops stop charging on purpose far more often than they fail. Heat protection, charge limits and a bad charger account for most cases before the battery itself is involved.
Step 1 — Read what the machine is telling you
- "Plugged in, not charging": the charger is recognised but charging is being withheld. Usually heat, a charge limit, or a charger that is too weak.
- "No battery is detected": the battery has dropped off the bus. Usually a connector, a swollen cell, or a dead battery.
- Nothing at all, no charging light: the charger, the cable or the charge port.
Step 2 — The charger
- Use the original charger. A 45 W supply on a laptop that wants 90 W will run the machine but never charge it under load.
- Check the cable at both ends for kinks and fraying, and try a different wall socket.
- If you have a multimeter, check the barrel or USB-C output voltage against the label. A charger that reads low is failing.
- USB-C laptops: try the charger in another port — charge ports fail, and the laptop may charge from a different one.
Step 3 — Heat and charge limits
Most laptops refuse to charge above roughly 40°C internal temperature. Let it cool with the lid open, on a hard surface, with nothing blocking the vents. Many also have a battery care limit (80% or 60%) in the manufacturer's utility or BIOS — when it is on, the laptop will sit at that level and report "not charging". That is working as intended.
Step 4 — Battery health
On Windows, open Command Prompt and run powercfg /batteryreport. It writes an HTML report with design capacity and full charge capacity. If full charge is below about 60% of design capacity, the battery is worn out and replacement is the honest answer.
Step 5 — Recalibrate once
Fully charge to 100%, use it down to shutdown, then charge uninterrupted to 100% again. This does not restore capacity, but it fixes the gauge inaccuracy that makes a healthy battery look empty or a flat one look full.
Stop and get it looked at if the battery is visibly swollen — the trackpad lifting, the case bulging, or the bottom panel no longer sitting flat. A swollen lithium battery is a fire risk. Stop using it, do not press it back down, and have it replaced.
Repair or replace
A replacement battery is typically $40–$120 for a laptop, and on most models it is a handful of screws. If the charge port is loose, that is a $30–$100 part plus labour. If the machine is over five years old and the battery is the only fault, replacing it is usually worth it — a worn battery is not a reason to replace a laptop.