Try another battery from the laptop's maker.
Your post is too light on details but the symptom is consistent with an old battery.
Bob
My laptop works with the AC adapter plugged in, and if I unplug it, it works on battery. The problem is that after I plug it back it, it won't charge the battery. And now the battery is at 60% since yesterday. I left it to charge all night but it's still 60%. It doesn't charge, even if the laptop is turned off.
The led that shows it's charging blinks as if it were charging.
When I unplug the AC adapter, in the tray it appears an icon indicating the level of charging of the battery. When I plug it back in, the small tray icon disappears and leaves instead another tray icon, Green Charger, which is set on charging at 100%.
Anyway, it doesn't charge. Please help!

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