This is a video demonstration from the University Of California Berkeley's High Performance Robotics Laboratory (HiPeRLab) of the flying battery drones they've developed that can dock with a larger drone and provide its battery power to that unit to keep it in the air for much longer, without the need for landing to recharge or swap batteries. With the use of multiple flying batteries, the team was able to keep the main unit in the air 4.7X longer before its own battery was depleted from the time it spent flying without an attachment. The future! "It looks bleak for humanity." *gulps from flask, winces, wipes mouth on shoulder* It really does.
Keep going for the video while I make my own flying batteries by lobbing a handful of dead AA's over my cubicle wall.
Thanks to cjcjcjcjcj, who's really been keeping on top of the latest in killer robotic technologies, and I appreciate that.