By Chris Hoffman, HowToGeek.com, October 19, 2016
Your Device Is Just Guessing Based on Your Current Usage
Laptops, tablets, and phones never seem to know exactly how many hours of power they have left. The estimate may jump from two hours to five hours before dropping back down to one hour. Even worse, the battery may suddenly die without warning.
Your device’s battery drains faster when it does more demanding things. All your laptop can do is monitor how fast its battery has been draining over the last several minutes and make an informed guess
