I have the full setup - controller, tablet, dock, and today received my controller batteries as well as a StarTech USB 3.0 to Gigabit Ethernet adapter.
The battery slab (more like a wafer, it's very light) has no indicator lights on it. No traditional "push button to see how much charge" like you would find on a decent Dell or IBM battery. The tablet can tell you how much battery charge is on the battery, but that means you have to put the tablet in the controller to check.
The battery does charge in the controller when the tablet is not in the controller, so that's a plus. It requires a controller or keyboard accessory to charge as the connector is different than the one on the power cable going to the tablet. Haven't had a chance to play games on it yet to see if it drains the extra battery first or both at the same time. It charges both at the same time at least.
Razer Edge and Edge Pro Owner's Lounge
