After some intense heating and very arduous prying, we finally get past the hefty adhesive holding the lower panel.

Surprise! The battery comes right off with the lower panel à la Retina MacBook.

With the power disconnected, let's get a closer look at this, the real power behind the Surface Book. With 51 Wh (6800 mAh at 7.5 V), the base battery provides nearly 3 times the juice as the tablet.

Both batteries combined give us 69 Wh, just a mite shy of the 74.9 Wh you'd get in this year's 13" Retina MacBook Pro.