Multiple reviews state Surface book’s battery life is around 3 hours when run in Clipboard mode. This is definitely way too short to provide true tablet experience, but I had a hope. That was an assumption I made such that when the clipboard/screen is plugged back into the keyboard, it recharges the screen/clipboard. The concern here I had was how efficient such charge is. If it took hours to recharge the clipboard vs. rapid charge to give additional 30 minutes use etc. Well, it turned out that I was worrying for irrelevant thing.