camping with CPAP (no electric hookup)

A lot of the previous posts give you good ideas of how to adapt power, but I think the more pressing question is your power source. If you are dry camping in a rig that has a single battery, you do not have much power to work with. While others on here can probably be more helpful with the specific math, my guess is that if this is more than a single overnight you will either need additional battery(ies) or a way to recharge during the day.

The pic above is the 24v inverter for my wife's unit. It came with quite a bit more goodies on the cord than mine did and it has a straight u p battery adapter.

The unit above is for my 12v Dream Station. Just a cord that plugs in.

My wife pretty much insists on the humidifier on hers. Drops me to 12.4 volts on 2 each 6v batteries in series. If I run the humidifer on mine, even set pretty low it drops me to 12.2v. Thats a little risky on my batteries so I jumped up to 4 each 6v batteries with the series and paralleled works much better.

Both my wife and I use CPAP machines in our rig and we normally have no hook ups. Many, if not most CPAPs run off 12v and have a transformer built into the cord to reduce the voltage from 120/240 down to what ever voltage the specific CPAP takes. Mine is 12v, so I ordered an adapter cord that goes from a standard 12v outlet(cigarette lighter) to the plug in on the CPAP. The adapter cord came from the CPAP manufacturer and it completely replaced my cord. My brides is a 24v unit and we got a 12v to 24v inverter from the manufacturer of her unit and both work perfectly. Easy as that. I did have to run 12v wire and outlets to each side of the bed so I can plug them in. I suppose if you wanted to you could put in an inverter direct from the batteries and plug your units into that. If you plan on using 110v appliances in your rig when your not hooked up to shore power that may be the best way to go. We don't use any 110v appliances at all when we camp so I have no inverter to plug my CPAPs into. I'm somewhat the minority on this subject as many like to have Mr. Coffee and microwaves etc.

I use the Transcend CPAP with the optional battery when dry camping.. It will last all night

My son's father in-law with his CPAP camped with us for a few nights. We had no choice we ran our little Honda 2000 generator all night. It wasn't bad because it doesn't use up a lot of gas and it's quiet. .

My CPAP runs off a 12vDC transformer from 120vAC. If you have adequate battery capacity (which you probably don't) you can run it off your house battery with a 12vDC adapter. Before I installed (4) 6vDC batteries, I would not use the humidifier function on the CPAP to save amps. You can also get a stand alone 12vDC (car) battery to power the unit, or the CPAP manufacturer probably has expensive 12vDC options.

Check the model of your son's CPAP. Many are actually run by 12 volt DC. Those models generally ave a "brick" in the household power cord which converts 120VAC to whatever DC voltage.
Many of the manufacturers offer 12 volt power cords for their machines.
If yours does not have that option the use of a small inverter 500-1000 watts will allow the unit to be powered by a battery via the inverter.
Suggest you get a pure sine wave unit to protect the CPAP.
For DW and I, we can run both of our units overnight on a single group 27 marine/rv battery. And we can then recharge that from any capable source the next day, from solar, to portable genny, to jumper cables for an hour to a running car or truck.

You'll need one of two things:
1. a dc adapter for the CPAP so it will run off of 12v dc.
2. an inverter to convert the 12v to 120v.

If he uses the humimdifier, 1 battery will just get him through one night.

It's been discussed here many times before, try the search funciton....