Wi-Fi is a battery hog. When stuck among a bunch of other Wi-Fi devices, most mobile gear will keep polling the access point for data while the other devices get their share. As Duke Today notes, "this means the battery drainage in downloading a movie in Manhattan is far higher than downloading the same movie in a farmhouse in the Midwest."New software, called SleepWell, puts the device to sleep while it’s waiting its turn, essentially allowing devices to grab everything they want at once and then hand off the download to the next device. Designed by grad student Justin Manweiler and his advisor, Romit Roy Choudhury, the system can add hours to the average battery.