Batteries are terribly inconvenient. The more power or endurance you need, the bulkier and heavier the battery has to be, and the more time it takes to recharge. Really, it’s the recharging that’s the problem, since until we develop a feasible ultracapacitor, any battery powered robot is going to have to spend a significant amount of time doing nothing but sitting around recharging its batteries. One way to get around this is to charge backup batteries external to the robot itself, but that process has generally been more trouble than it’s worth, since batteries tend to be heavily integrated into the structures of robots. Way back in September of 2009, we posted about a conceptual pet care robot that used an external battery swapping method, which was very cool, but it didn’t look like it had a prayer of ever being realized. The video above shows an actual external battery swapping system in action, on a marXbot, which is part of the Swarmanoid project from EPFL. Using a rotary loader, marXbot can swap out its battery in seconds while a capacitor keeps the robot powered. The batteries charge on the loader, so by the time the spent battery makes it all the way around, it’s been recharged and is ready for another robot in need of a fresh meal. Somewhat ironically, swarms of robots are arguably least dependent on power system restraints, the idea being that you can just have other robots in the swarm cycle in and out to charge. However, the more robots you have, the more charging infrastructure you need. With this battery swapping system, the number of robots that can recharge at once is limited only by the number of batteries in the system, as opposed to the number of charging stations or outlets or something, […]