For those with the Surface Book 2 with a usb-c port, Amazon is running a great deal on the Mophie Powerstation XXL usb-c at $90MM vs. retail at $150. Mophie's website also appears to be running a sale, but it's still higher priced than Amazon. I got mine yesterday, and it does charge my Surface Book 2 via usb-c. The Mophie is substantially lighter and smaller than products made by companies such as Anker but is smaller at 19,500 vs. 20,000-26,500 mah. I think the trade off in terms of capacity vs. size and weight is worth it. One thing to keep in mind is that on the battery, the Surface Book believes it's plugged into the wall, so it's running at higher power consumption and will drain the Mophie at it's 30W max output level. That means the Mophie is going to add maybe only 2.5 hours of battery time if you forget to adjust the settings. Separately, I'm not sure I really like the Base Qi. It's impossible to remove without a tool and magnesium is relatively soft. So yanking it out and in more than a few times is highly likely to scratch the side, which I'm paranoid about.