Cornell’s Ranger Robot, world record holder for the longest walk by a robot on a single charge, has smashed its own personal best by logging 40.5 miles without stopping, recharging, or even being touched. Over the course of almost 31 hours, Ranger ambled along at a not-so-blazing 1.3 miles per hour for 397.75 laps around a running track, but managed to make the whole trek using just a nickel’s worth of electricity.

The robot’s previous record, set in July of last year, was just 14.3 miles. Ranger’s handlers at Cornell were able to squeeze more mileage out of their robot by improving its efficiency through better overall control. Ranger gets by on far less power than most legged robots because, for the most part, its legs swing freely, catching the robot as it falls forward and pushing it into its next step.