CPAP machine and batteries

My CPAP machine, a Respironics run off both 120 volt and 12 volt. The machine has a converter built in that reduces the voltage to 12 volts. At home I plug it into the wall 120V but in either of my RVs I use a 12 V plug in an plug this directly into the side of my CPAP machine. I also have a 12V jump start setup, bought from Sears that has a 12 V outlet on it. I keep this setup charged and have used it a couple of times for tent camping or just as a backup if the furnace runs down my house battery. The jump start will run my CPAP for three nights before needing to be recharged. I often will recharge the battery in the jump start, by starting my truck engine, connecting the jump start cables to the truck battery and switch the jump start unit to the on/start position. I have twin 135 amp alternators on my truck so it doesn't take long to recharge the jump start battery. Probably not the best for longevity of the jump start battery but I have been doing this for several years now and it still works. LOL

CPAPs not using heat or humidity, seem to use very little power to run all night.