Cpap and camping

wa8yxm wrote:
Ok, Since it is 12 volt forget the Inverter, use 12 volt direct.. Both the inverter and the power converter (Wall wart or brick) are less than 100% so you loose power converting to/from 120vac.

Now 6.6 amps means 6.6 amp hours per hour. or in an 8 hour night

52.8 amp hours.JUST FOR THE CPAP..... A Group 27 at best has 95 Amp Hours..

You can only safely use about 25,, YOu need more battery

Upgrading to a pair of GC-2 in series gives you 220 amp hours (Give or take about 10) and over 100 usable.. That's more usable battery power LEFT OVER come Morning than you now have in the RV. I highly recommend the upgrade.

the 6.6A draw is the max draw with a safety factor for worst case operation conditions. low line voltage hooked to AC, max humidifier heater draw etc.

My resmed has a 4A rated draw. Actual draw over 8 hrs with humidifier off is less than 1A. about 6AH per night. it goes to about 2A average draw with humidifier. for 12AH/night

without the humidifier on, I can run it 4 nights off a 250WH (20AH) lithium battery pack.

I suspect the OP's is well under 6A draw worst case on 12V. likely down near 1A which is very common from those of us who have cpaps and have measured the AH draw per night.