Some devices are better at understanding how much power they have. The hardware that monitors how much capacity the battery has left may have an inaccurate estimate, which why a device might die when the operating system is still reporting 10% or even 20% battery power left. In other words, they won’t hold as much power. RELATED: How to Calibrate Your Laptop's Battery for Accurate Battery Life Estimatesīatteries suffer wear and tear as you use them. If the Battery Dies Without Warning, It Doesn’t Know How Much Juice it Has It can’t predict the future, only guess based on current conditions.
It’s similar to why progress bars can be so inaccurate. In other words, your device makes an estimate based on the current rate of battery drain. Even if you’re just browsing the web, some websites–especially ones with video ads–use more system resources than others. For example, Windows might be installing updates–that will use more CPU resources, drain battery power more quickly, and lower the estimate. This estimate can also fluctuate based on the work your computer is doing in the background.
