The Revolve 810 delivered four hours and two minutes on a charge. Years ago, that would be groundbreaking, but today it's middle-of-the-road. We'd chalk this up to its third-gen Intel Core i5 processor. The far more power-efficient 4th-gen Haswell CPU would certainly have delivered longer time on battery. We employed our standard test process: We played an AVI movie file continuously using VLC Player with the screen cranked to full size and brightness. We left all other HP power-saving features unchanged. The Wi-Fi radio remained on during playback, and we occasionally checked email and browsed the web.