Lasted a solid 8 hours on my AirSense 10 at high pressure, but with the humidity and hose heater off. The battery was down to 1 bar at that point, so I guess 1 night is what I'll get it of it. Can't complain about that. It is smaller and lighter than I would have expected given the energy storage. Looking forward to using this in my RV and on international trips to locations with sketchy power availability.