Why Is My Laptop Suddenly Eating Up the Battery?

By Nick Flegg

Watching a DVD on your laptop can drain the battery significantly.
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Your laptop's battery life can be influenced by the setup of your machine, the applications you are running or even the age of the battery itself. You can boost the efficiency of your battery by optimizing your system settings or by shutting down unwanted programs. You can even calibrate your battery to ensure you are receiving a more accurate reading.


The screen on your laptop can use more power than any other part of your machine. Some laptops adjust the brightness of your display automatically depending on your surroundings. If your laptop is running with the screen brightness at the highest setting, you should turn it down to a comfortable level in order to extend battery life. You can also alter your system settings to ensure your computer lowers the brightness of the screen automatically when not in use.

Background Applications

You may be running applications in the background unintentionally without realizing it, and this can have an impact on the battery life of your laptop. You can check your active processes by opening Activity Monitor on a Mac or Task Manager on Windows. Close applications that you aren't using, including connectivity settings such as Wi-Fi and Bluetooth. Note that some computers may run system tasks automatically -- for example, Macintosh computers occasionally index your files in Spotlight, while Windows computers automatically install updates.

Power-Hungry Applications

Some applications use more power than others, and this can cause your battery meter to fluctuate. Your system's battery display can lag behind your real-time activity, so if you have recently changed an application, your battery display may take a little bit of time to catch up. Power-hungry activities include watching videos, editing photos and listening to music. Multitasking can also put extra strain on your battery, so try to stick to one task at a time if you're energy-conscious.

Old Battery

It is possible that your battery is the cause of the sudden drainage, rather than the computer itself. Modern laptop batteries last for a certain amount of cycles before the charge they can hold begins to decrease; Apple claims its notebook batteries can deliver 1,000 cycles -- approximately five years of usage -- before seeing a diminished return. You can check your total battery life by installing an application such as CoconutBattery for Mac or BatteryCare for Windows. If you're always running out of power, changing the battery might make a difference.

Calibrate your Battery

If your battery meter is displaying inconsistent readings, try calibrating your battery in order to fix the problem. To calibrate your battery, let it run down to empty until it automatically switches itself off, then recharge it back to 100 percent without unplugging. Repeat this cycle a few times, with a couple of hours' rest between each cycle.