 Until recently, this required a Waterloo co-worker to plug it in before leaving for the night.In May 2008, Ian constructed a charging bay out of lumber that Ivan "drives" into - copper bars attached to the robot connect to copper springs on the charging unit which are directly connected to the battery charger and enabled through a relay circuit so that the charging bars are not live unless the robot is in the bay.The charging bay permits Ivan to recharge the robot at his convenience, and without assistance.