If the laptop recognizes that the charger is connected but the battery percentage isn't increasing, there are a few things worth checking before assuming the battery has failed.

First, check whether the laptop shows “Plugged in, not charging” or whether it doesn't recognize the charger at all. If possible, inspect the charging cable, adapter and charging port for damage or a loose connection.

Some laptops also have a battery protection or charge-limit feature that intentionally stops charging around 60–80% to extend battery lifespan. Check the manufacturer's battery or power-management settings to make sure a charging limit hasn't been enabled.

If the battery is very low and still won't charge, shut the laptop down completely, disconnect the charger for a short time, reconnect it and try again. A compatible charger with insufficient wattage can also power a laptop while failing to charge the battery properly.

If the laptop works while plugged in but immediately shuts off when the charger is removed, the battery itself may be heavily degraded or faulty.

For anyone with this problem: what percentage is the battery stuck at, and does the laptop show that the charger is actually connected?

Thanks, the charger wattage is something I hadn't considered. I always assumed that if Windows detected the charger and the laptop stayed powered on, then the charger was supplying enough power.

Is there a reliable way in Windows to check the actual health of the battery and tell whether it has lost a significant amount of its original capacity? I’d like to rule that out before replacing the battery.

Yes. Windows has a built-in battery report that can give you a good idea of how much capacity the battery has lost over time.

Open Command Prompt or Windows Terminal, then run:

powercfg /batteryreport

Windows will create an HTML battery report and show you where it was saved. Open that file in your browser and look under Installed batteries.

The two numbers I'd compare are Design Capacity and Full Charge Capacity. Design Capacity is roughly what the battery was designed to hold when new, while Full Charge Capacity is what it can currently hold.

For example, if the design capacity is 50,000 mWh but the full charge capacity is only 25,000 mWh, the battery is now holding roughly half of its original capacity. That would be a strong indication of significant battery wear.

Also check the report's Battery capacity history and, if available, cycle count. Those can help show whether the battery has been gradually deteriorating.

One thing to keep in mind: a worn battery can still charge normally but simply have much less runtime. If the battery refuses to charge at all, I'd still check the charger, charging limit and hardware before concluding that battery wear alone is responsible.

If your battery is charging but it's simply taking much longer than normal, that's slightly different from a battery that refuses to charge at all. Charging speed can be affected by the charger, cable, power source, battery condition and even device temperature.

We have a related discussion about diagnosing unusually slow charging here:

https://anyoneelse.592gy.com/community/phones-tablets/phone-charging-slowly-even-with-the-original-charger/

It's focused on phones rather than laptops, but some of the same basic principles—especially checking the charger, cable and battery condition—can help when narrowing down a charging problem.