Based on the description on their site, the controller includes a built-in battery: "8.39 Wh Li-ion battery, 35+ hours of gameplay... "
That was disappointing for me. Specially condidering the Steam Frame's controllers make use of AA batteries: "One replaceable AA battery per controller, 40hr battery life"
AA Batteries might not be as convenient to use, but being able to replace them is a great advantage. All my Xbox360 controllers still work fine, but none of my PS3' Dualshock 3s.
The official docking station could be used to recharge (rechargables) AA batteries so the functionality could remain the same.
According to reports it is. Not as easy as a hot-swapable one, but close. You just have to remove the back panel, pop it out and put the new one. No adhesive involved.
Week one, somebody's going to release a CAD file for a 3D-printable shell with a removable battery cover.
If JSAUX or ExtremeRate did not already made one. Hell, DBrand already announced a companion cube skin for the Steam Machine. 😂
Amazing. This should become industry standard.