Multiple CPAP’s on One 12v Socket?

[LongIslandCamper]

I have an air sense 10 that I’ve been using for two months now. Heater set to 81 and humidity to 3. Air I believe is 6-8. I finally used it last night with a meter and it said it used .22kwh over the span of 9.10 hours. It looks like the draw was about 18.3ah.

Does that sound about right? My wife will be starting to use the same machine soon and I figure the settings will be about the same because we had similar sleep study results.

How can we go about powering our machines when boondocking? We have one 12v outlet under the tv in the wall outside our bedroom. Can we possibly run one or even BOTH machines from that single 12v outlet by using a splitter?

We do have a second 12v outlet at the rear of the camper. Should we look into a 12v extension cable so that each machine can use its own 12v outlet?

For what it’s worth, we will be running 2 100ah lithium batteries that will be topped off every night via solar and/or generator.

[RogerR]

For best advice, post make, model and year of your RV.
Based on mine I would run a direct line (with fuse or breaker) from the battery to two outlets. My single outlet has a tiny wire and it might overheat or blow the fuse. Plus more convenient to have them where you need them and no wires to trip over.

Post how many feet the run would be and I bet some one with more electrical knowledge will suggest the minimum and recommended wire and fuse sizes. While your running these, add a usb charge port!

[Russc25]

None of those numbers are what you actually need. Outlet and wire capacity only needs to know amps. Figuring out if your battery will last the night, that's where you need AH and Kwh.

If you pulled 18.3ah over 9.1 hours that comes to about 2 amps per machine.

Most 12v cigarette-lighter type outlets are 10 or 15a (I'd aim low given how most RVs are built).

So if you measured and posted right, you should be fine running 2 CPAPs.

[LongIslandCamper]

We have a 2013 26rls

So my first test was 9 hours long. My wife will be using the same machine starting this weekend with the same settings so I simply doubled the number and this is what I came up with for the first night.

.44kwh 36.6ah and 4.07a with all features running

Last night I turned off the heated hose and humidifier. The numbers below are double what I recorded because I’m preparing for two machines. This test was also 9 hours.
and .08kwh 6.6ah and .73a

Does that look right?

Would I be totally fine using a 12v splitter cable to power both machines if we turn off the heated hose and humidity?

[paulrlf]

You could use a separate LiFePo4 battery that will power the CPAP. check out this link
https://exppropower.com/collections/...-cord-included. I use a smaller LiFePo4 battery that gives me 4-5 nights without a heater when boondocking. Plug into the 120v outlet and can recharge it during the day. P.S. mine is the EXP pro 96

[Rambling Man]

Originally Posted by RogerR

For best advice, post make, model and year of your RV.
Based on mine I would run a direct line (with fuse or breaker) from the battery to two outlets. My single outlet has a tiny wire and it might overheat or blow the fuse. Plus more convenient to have them where you need them and no wires to trip over.

Post how many feet the run would be and I bet some one with more electrical knowledge will suggest the minimum and recommended wire and fuse sizes. While your running these, add a usb charge port!

Before you attempt to get a new wire from the batteries to the area where you need the CPAP power check for wiring under the bed. That's where most of the electrical is in our 2022 27U Greyhawk. In our case it was easy to connect to 12 volts at the power junction for the inverter, add a 5 amp fuse, and run 12 gauge stranded wiring to the 12 volt socket. 12 gauge copper is good for more, but it is good practice to fuse to fuse only slightly higher than the device draws.

[Rambling Man]

OK, I messed up on my first ever forum post. I didn't see this quick reply box before I entered text and scrolled down.

[CommoSGT]

My Jayco was manufactured in 1994. USB wasn't a thing in 1994. I had to add USB jacks and while adding the USB jacks I also added 12VDC jacks.

The first photo is of 2 boxes I made and installed on both sides of the bed (I left my hand in the photo for a reference for size). This box has "2 USB jacks with a voltmeter in between the USBs", a "cigarette lighter" jack and a "Barrel" 12-volt jack. If memory serves, I ran a 20-amp fused 10-gauge wire to the bedroom from the fuse panel and split to the two boxes (second photo).

I purchased all the components from Amazon. I am unable to access my Amazon account now because it got hacked and I no long have access to my purchase history to include links to any components.

The only thing I don't like about the box, is the USB voltmeter readout is very bright when trying to sleep but has to be on to charge the phone. There is a switch to the right of the right of the meter that turns off the USBs and meter. The simple fix is to take a black washcloth and cover it at night.

I found the CPAP cables on either Amazon or Ebay for the CPAP (RESMED 10) we have, which require 24VDC. I also have 2 machines I leave in the RV that require 12VDC, so we don't have to take the machines from home.

[Jagiven]

Nice job, I added just the 12v aux receptacles. I then just insert a automotive adaptor for our phones. I too use a cpap.