Batteries wear out. After two or three years of daily use most laptop batteries hold noticeably less charge, and heat speeds that up. Some of it you can fix, and some of it means a new battery.
Check the battery's real health (Windows)
- Click Start, type
cmd, open Command Prompt. - Type
powercfg /batteryreportand press Enter. - It saves a report and shows where (usually
C:\Users\yourname\battery-report.html). Open that file in your browser. - Compare Design capacity with Full charge capacity.
If the full charge capacity is below about 60 percent of the design capacity, the battery is worn and replacement is the real fix. On a Mac, hold Option and click the battery icon to see its condition.
Make the charge last longer
- Lower the screen brightness. The screen is the biggest drain on most laptops.
- Turn on Battery saver (Settings, System, Power & battery) or Energy saver.
- Close browser tabs you are not using; video and heavy websites use a lot of power.
- Unplug devices you are not using: a USB mouse, a phone charging from the laptop, an external drive.
- Check Settings, System, Power & battery, Battery usage to see which apps use the most.
Why it gets hot
- Blocked air vents. A laptop on a bed, cushion or your lap cannot breathe. Use it on a table or a hard tray.
- Dust in the fan. If the fan roars all the time, the cooling system is probably full of dust. A technician can clean it, usually for a small fee; in dusty harmattan months it builds up faster.
- Room heat. Laptops struggle in a hot room or direct sun. A cheap laptop cooling pad helps.
- Too many programs running. See laptop running slow.
A hot laptop slows itself down to protect its chips, so overheating often shows up as sudden slowness too.
Charging habits
- It is fine to keep a laptop plugged in; modern laptops stop charging when full. Many (Lenovo, Asus, Dell, HP, Samsung) have a setting in their own app to stop charging at 80 percent, which extends battery life if the laptop stays on the charger all day.
- Avoid leaving it fully drained for days.
- Use the original charger or one of the same wattage from a reputable brand.
When a battery is dangerous
A swollen battery pushes the keyboard or touchpad up, or makes the case bulge or no longer close properly. Stop using and charging the laptop, keep it away from anything flammable, and have the battery removed and replaced. Do not puncture or press on it.
Replacing the battery
Ask for a battery that matches your laptop's exact model number (on the sticker underneath). Cheap unbranded batteries often hold less than their label claims. Many laptops now have the battery inside, so replacement is a technician's job.