I made this flat bottomed portmanteau to carry my CPAP machine and batteries. I have found this set-up works fairly well for me for trekking and events.
I use my CPAP machine without the humidifier. If I’m over 8,000 feet above sea level I have to use some Oxygen so I have a small regulator and wrench. The batteries I use are a 1270 Power Sonic. They are 12 volts and 7 amp hours. They last about 8 1/2 hours which gives me a fairly good nights rest.