12 Volt Powered Machine for Camping

At home my wife uses a ResMed machine but it is the wrong voltage to use when we go camping or sailing, so we purchased a DeVilbiss IntelliPAP DV51. The machine has worked great. The amperage draw off of a 12 Volt battery measures 2 amps when the CPAP machine is set at 7 pounds of pressure. The total usage for an 8 hour sleeping period is therefore 16 amp hours. I made a 35 foot extension cord that clamps onto the car, truck, RV, or boat battery. It is enough length to reach our tent when camping in most situations. The other end of the extension cord, where the CPAP machine plugs in, terminates with an automobile style 12 volt socket.
The DeVilbiss IntelliPAP DV51 CPAP machine does not heat the water when working on a 12 volt system, but we still run the air over the water reservoir and it seems to humidify the air enough to satisfy my wife's breathing needs.
The issue becomes one of keeping the battery charged. In most vehicles the charging rate is high enough to restore 16 amp hours of energy in a couple of hours of driving. If we are not driving, I hook up solar panels to recharge the system during the day. I wire the panels back into the extension cord, and therefore, never have to disconnect from the battery terminals.
We have had no problems with this set up. The DeVilbiss IntelliPAP DV51 is our go-to traveling machine, working both in a hotel room or hooked to our vehicle.