Laptop battery won't charge
This is very common, and most of the time it's the cable, the outlet or a setting rather than a broken battery.
Be careful: If the charger or laptop gets very hot, smells of burning, or the battery looks swollen, unplug it right away, don't charge it, and get in-person help.
What to do
Step 1: Plug the charger straight into a wall outlet you know works, not a power strip.
Step 2: Check every part of the cable is pushed in firmly, including where it goes into the power box in the middle of the cable.
Step 3: Look for a charging light on the laptop. Try a different outlet if there's none.
Step 4: Look gently into the laptop's charging port with a flashlight. If there's lint, ask a helper to clear it with a wooden toothpick, never anything metal.
Step 5: Restart the laptop with the charger plugged in.
Step 6: If it says Plugged in, not charging at around 80%, your laptop maker's app may have a battery-saving limit turned on. Open the maker's app (for example Lenovo Vantage, HP Support Assistant, MyASUS or Dell's power app) and look for battery or charging settings.
Step 7: Install updates in Settings, then Windows Update, as battery and charging fixes often come this way.
Still stuck? If it still won't charge, try a known-good charger of the same type, then contact the maker's support or a trusted repair shop, as the battery or charger may need replacing.