Well we did our first cpap camping trip this last weekend. What a success! I use just one deep cycle battery for my RV and it has built in cigarette lighter outlets inside. The first night I connected my dc adapter to my cpap and hung the 10ft hose from the curtain rod. I did not use the humidifier upon a recommendation here. I woke up 10 hours later (longer than I have slept since I was a teenager) with my cpap still running strong. No dry sinuses or anything from lack of a heated humidifier. I just used the humidifier as a passover. After I got up I checked the battery and it was still 3/4 charged. I could have gone at least 3 nights on that battery!!! I was thrilled and will be doing much more camping this summer.