Why is the remaining battery incorrect sometimes w/ Surface Book?

[Windows Central Question]

I am at around 70% and my estimated remaining hours keeps changing from about 3 different choices... 2 hours, 7 hours, and 9 hours. Is Windows 10 just confused because the Surface Book has multiple batteries?

 

[Chintan Gohel]

I think it's based on your usage. For example, if you start an intensive task, the battery app will look at the current consumption and give a short estimate. If you're barely doing anything, then it will be a longer estimate