Laptop warns of low charger power? What to check

Your laptop is plugged in, but a warning says the charger is too weak, charging slowly, or unable to provide enough power. The battery may still charge, charge very slowly, or lose power while you use the laptop.

The warning often means the laptop is receiving less power than it expects. The charger, cable, port, dock, or a demanding workload can all contribute. Start by comparing the charging rate with the Charger & Cable Test, then check the parts of the setup one at a time.

Compare the charging rate

1. Open the Charger & Cable Test on the laptop that shows the warning. The browser must be able to report battery information for the test to appear.
2. Connect the charger directly to a wall outlet and the laptop, not through a dock or hub. Keep the laptop awake and leave the test open long enough to see a charging rate.
3. Note the rate in percent per minute. If you have another compatible charger or cable, test it under the same conditions and compare the readings.
4. Change only one part at a time. For example, keep the charger and outlet the same while swapping the cable, then keep the cable the same while swapping the charger.

Do not force a connector or continue testing a cable that is frayed, bent, unusually hot, or smells burnt. The browser test measures how quickly the battery percentage changes. It does not read the charger's exact wattage or certify that the charger is electrically safe.

What the result means

The rate improves with another charger

The first charger may not provide enough power for this laptop, may be failing, or may be splitting its output between several connected devices. Check the laptop maker's recommended charger rating and the output printed on the adapter. A higher number on a charger label does not guarantee compatibility, so use a model that supports the laptop's required voltage and charging standard.

The rate improves with another cable

The original cable may not support the power level the laptop needs, or it may be damaged. This is common with USB-C: the plug shape alone does not tell you how much power the cable can carry. Use a cable rated for the laptop and charger, and check whether the warning goes away.

The rate stays low with different chargers and cables

The laptop may be limiting charging because it is hot, under heavy load, or near a battery level where charging naturally slows. The charging port, battery, or internal power circuitry could also be at fault. Repeat the comparison with the laptop cool and idle before assuming a part is broken.

The battery percentage does not rise

A full or nearly full battery may charge very slowly, and some laptops pause charging at a set limit to protect the battery. If the percentage falls while the charger is connected, the laptop may be using power faster than the charger supplies it, or the charger connection may be intermittent.

How to fix the warning

1. Connect the charger directly to the laptop. Remove any dock, hub, monitor, or extension that sits between the charger and computer. Some docks pass less power than the laptop needs, even if the dock itself is working normally.
2. Check the charger's rating. Compare its output with the laptop maker's recommended adapter. For USB-C, check the charger's supported power output and the cable's rating. Multiport chargers may provide less power to the laptop when another device is connected.
3. Try another supported port and cable. Some USB-C ports transfer data but do not accept charging, or accept less power than another port. Check the laptop manual for the charging port, then test with a known compatible cable. Do not wiggle a loose connector to keep it charging.
4. Reduce the laptop's power use for a comparison. Close demanding games, video exports, and other heavy tasks, and let the computer cool on a hard surface with its vents clear. On Windows 11, check Settings › System › Power & battery. On a Mac, check System Settings › Battery. Power settings can affect use and charging behavior, but they do not show the charger's exact wattage.
5. Restart and check for a persistent warning. Disconnect the charger, restart the laptop, and reconnect it. If the message remains, install firmware or system updates only from the laptop maker's official support channel. Do not update firmware while the laptop has an unstable power connection.

When the charger or laptop may need repair

If one compatible charger consistently charges normally and another consistently triggers the warning, stop using the weaker or unreliable unit. Replace it with a compatible charger from a reputable source. If several known-good chargers and cables trigger the same warning, the charging port, battery, or laptop power circuitry may need service.

Stop using a charger or cable that becomes excessively hot, sparks, has exposed wires, or smells burnt. If the laptop or connector gets unusually hot, unplug it when safe and arrange a repair. Do not open the charger or laptop to investigate its power circuitry.

Why a laptop can reject a charger that fits

A charging connector that fits is not proof that the charger can supply enough power. With USB-C, the laptop and charger negotiate a supported power level, and the cable must also be suitable for that level. A barrel-style charger may need the correct voltage and, on some models, a supported identification signal. A lower-power charger can sometimes keep a laptop running while the battery charges slowly, but a demanding workload may use more power than it supplies.

For a useful comparison, test with the same laptop, similar battery level, same workload, and same outlet. The charging rate is a clue about the complete setup, not a direct measurement of charger output.