CPAP machine

Are you looking to run the CPAP machine off of batteries versus plugged into power?

Well, there are battery powered Cpap machines that might work for you.
What you need probably is an INverter. That takes 12VDC and converts it to 120VAC. Depending on the amp draw of his machine a 1000 watt unit will probably work just fine. INverters need to be placed as close to the battery bask as possible. Then its a matter of adding an inline fuse between the batteries and INverter and using sufficiently large gage wire to carry the load. From the INverter you can simply run a dedicated line to new receptacle near the bed.

some cpap manufactures have a 12v adapter one can get. hooks to 12v source and powers machine. some even shut unit off if voltage of battery drops to low.

We use a cpap and Dw a Bipap, powering them from inside a rv is not difficult.
If the unit has a brick (large plastic box transformer) in the cord check the voltages on that. It likely is a 12 volt unit. If so, you can get 12 volt power cords to allow you to connect it to the trailers 12 battery power. My Respironics CPAP is listed as drawing a maximum of 5 amps at 12 volts, since I dont use the humidifier, it actually draws less than half that.
12 volt cords are available from most manufacturers for their models, you just need your model # .
If your unit will require 120VAC an inverter will be required to convert the 12 volt DC from the battery to 120 VAC, a pure sine wave inverter would be the safest for protecting the machine and will need to be more than 300 watt continious in size, preferably 500 watts.
Either way you will need a good battery/batteries on the RV with at least 40 amp/hrs available to maintain power for the unit, and a suitable method of recharging during the day.

cpu266 wrote:
some cpap manufactures have a 12v adapter one can get. hooks to 12v source and powers machine. some even shut unit off if voltage of battery drops to low.

what make/model cpap does he have?
bumpy

Do you have a DC power outlet near the bed?

Here's an example of a DC power cord for a CPAP (may not be the correct one for your husband's particular machine):
DC power cord

The CPAP machine must be DC compatible to use this cord (or similar). Check the manual.

We have a DC outlet at our vanity, a bit far from the bedside. So we moved the CPAP machine farther away and bought a 10-foot air hose. That, with the 6-foot DC power cord reaches my spouse.

i use a resmed airsense 10. resmed makes a power brick that allows the unit to run off 12v battery and shuts the unit down if battery voltage drops to low - i think around 11.+ volts. they got for about $120 - found some on amazon.

the power brick is also made by resmed.

Do you not have a regular outlet by the bed?
Are you camping off-grid?

My DW and I both use Resmed Airsense 10 CPAPs. They operate on 24 volt. Our camper does not have 12v outlets by the bed, so some wiring was going to have to be done. I have an inverter that would run both CPAPs, so first thought was to get a 12v gel deep cycle and set it at the foot of the bed with the inverter and run off those. First try showed that there was not sufficient room to set both there. I was still reluctant to run the CPAPs off the camper battery as we can be off grid for several days as we travel. I got 2 of the 12v Resmed bricks, ran an extension cord from the pass through storage into the bedroom area and attached 12v female plugs on 120v type plugs that would plug into the extension cord. I set the battery in the pass through storage area, alligator clip the extension cord onto that, and with it carry 12v into the bedroom area, where the CPAPs plug in. During the day as we travel, I put the battery in the back seat of the truck and charge it with a trickle charger plugged into the truck 120v outlet. It's always charged by Noon. This may be a "round Robin Hood's barn" way of doing it, but it works for us.