Can Macbook Pro Retina turn on without the Battery?

Hey, folks. My trackpad went bad so I had to remove the battery in my MBPr to get to it. I chucked the battery because it was at 70% capacity, but I guess I was premature. I've got the computer plugged into the wall, but now it will not turn on. Is the battery required for the machine to start? Or did I somehow kill the computer (which wasn't touched) while removing the battery?