I checked the amp draw on both of the units. The amp draw must include the Humidifier. If it didn't the two units would use 106.72 amps over an 8hr period. That would have taken my to 50% of their capacity. That has not happened. I have used the two Phillips Respironic units quite a few times. The Resmed unit uses about 1.25 amp hr. more. I am thinking with my Phillips Respironics and the Resmed unit both running w/o Humidifiers on would be just about the same(it will draw 10a more over night) as the two Phillips units w/o the Humidifiers on. Thinking it will be OK.
Finishing up from my perspective..........the one thing I am not good at is unplugging the unit from the 12v for traveling. I have logged quite a few miles with it plugged in, but I will need to get better. These things are a bit too pricey to be irresponsible with!