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Anyone use a CPAP when they anchor or moor out?

Jul 4, 2015
414
Hunter 34 Menominee, MI; Sturgeon Bay WI
Hi;
Have a CPAP that draws 4A at 120V . If I buy an inverter that translates to roughly 40 A at 12 volts. The invertor though has to be hooked up to the battery and it would require a 10 foot run of 10 Ga wire. Besides putting a permanent setup on my boat, it would be a real pain to lug all this junk on flights etc. Anybody have a better solution?
Thanks.
Ilan
 
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May 17, 2004
3,485
Beneteau Oceanis 37 LE Havre de Grace
That’s going to require a pretty serious battery bank in addition to the wiring. 40 amps for 8 hours is 320 amp hours. If that’s your only load and you have lead acid batteries that means a bank of at least 640 amp hours.

Also pay attention to voltage drop on the 12V wires. Do you mean 10 feet from the batteries to the inverter, or 10 feet total round trip? Voltage drop applies to the full round trip length. The Blue Seas calculator at Circuit Wizard - Blue Sea Systems suggests you’d be ok with 10 gauge only if it’s 10 feet round trip and you can handle 5% voltage drop. 10 feet one way and 3% voltage drop would require 6 gauge. I suppose you could reduce the round trip length by putting the inverter closer to the batteries and running the 120V wire to the machine itself.
 

SFS

.
Aug 18, 2015
1,979
West Marine Kayak Tampa Bay
I slept with mine every night for the 6 months we were on the boat in 2018, most of which was at anchor each night. There are better options than planning for, buying, installing, and maintaining an inverter, in my opinion. Why not plug into 12V DC, which is what I did?

In fact, in preparation for moving onto the boat, I purchased a gently used, refurbished Respironics Dream Station AutoCPAP from the amazing folks at secondwindcpap.com. I chose this unit based on recommendations (see a wonderful website below), how much current it drew, and the price of the available 12VDC cord (which was only about $25, instead of the $100+ for the 12VDC cords for other manufacturers machines). I could use it about 3 nights without drawing our 2 house batteries (2 X 160 AH) down enough that I wanted to run the engine to recharge the batteries. YMMV, as all of our lights were LEDs, and we our only other current draws were recharging phones and running computers (on 12VDC) while at anchor.

There are threads about CPAP use on cruising boats on the following website (and the search function is easy to use):


I found the site very helpful, and the folks at SecondWind were wonderful. Their customer service is unparalleled. As to costs, I think I paid about $400 for a (then) state of the art auto-titrating CPAP. And all I did was plug it in - easy. Don't know what your all-in costs would be on the inverter and install, but for me, the decision was easy. Of course, it helped that I needed a new CPAP, mine was 8 years old at the time. I didn't involve my medical insurance, just paid out of pocket. Cheaper and quicker.

If I can help in any way, send me a PM and give me a day or so to respond, as I am out of the country.
 
Apr 11, 2010
860
Hunter 38 Whitehall MI
My cpap (and I assume most do) uses a transformer to step the 110 v down for use in the machine. So,your suggestion of just running It off 12v directly makes perfect sense.
 
Feb 10, 2004
3,510
Hunter 40.5 Warwick, RI
I use a CPAP that can run on 120VAC or 12VDC. A eight hour night draw is about 15AH from my house bank. If you don't have a 12V CPAP, get one. They don't cost extra over a 120VAC unit. Do watch the price of the 12V cord however as SFS pointed out above. I also have a friend who has a 120VAC-only unit and he runs this from a 400W inverter on board. I don't think it draws more than 2A or maybe 25AH overnight. Connect your CPAP and actually measure the 12V power that it requires. If the 4A spec on yours includes a humidifier, skip that option unless you absolutely must have it.
 
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Mar 26, 2011
2,945
Corsair F-24 MK I Deale, MD
Hi;
Have a CPAP that draws 4A at 120V . If I buy an inverter that translates to roughly 40 A at 12 volts. The invertor though has to be hooked up to the battery and it would require a 10 foot run of 10 Ga wire. Besides putting a permanent setup on my boat, it would be a real pain to lug all this junk on flights etc. Anybody have a better solution?
Thanks.
Ilan
I doubt the 4 amp figure. Check the plate again. That is probably at 12v. My wife's is 4A at 12V. Ran it on the house bank hundreds of times.

We found it handier to extend the hose than the cord; the head of the bed is far from the shelf.
 
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Jul 4, 2015
414
Hunter 34 Menominee, MI; Sturgeon Bay WI
I doubt the 4 amp figure. Check the plate again. That is probably at 12v. My wife's is 4A at 12V. Ran it on the house bank hundreds of times.

We found it handier to extend the hose than the cord; the head of the bed is far from the shelf.
You're right! I looked again and transformer output is 3.75A at 24V. That translates to 7.5A at 12V.
 
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Jul 4, 2015
414
Hunter 34 Menominee, MI; Sturgeon Bay WI
You folks are terrific. I went about this all wrong and actually purchased an inverter etc. Going to go a different route and look into the portable 12 v machines for travel. I initially inquired with my doctor about 1 year ago and was told that the travel machines are far to noisy and will keep me awake.
Have to get a move on as my trip is in two weeks!
I slept with mine every night for the 6 months we were on the boat in 2018, most of which was at anchor each night. There are better options than planning for, buying, installing, and maintaining an inverter, in my opinion. Why not plug into 12V DC, which is what I did?

In fact, in preparation for moving onto the boat, I purchased a gently used, refurbished Respironics Dream Station AutoCPAP from the amazing folks at secondwindcpap.com. I chose this unit based on recommendations (see a wonderful website below), how much current it drew, and the price of the available 12VDC cord (which was only about $25, instead of the $100+ for the 12VDC cords for other manufacturers machines). I could use it about 3 nights without drawing our 2 house batteries (2 X 160 AH) down enough that I wanted to run the engine to recharge the batteries. YMMV, as all of our lights were LEDs, and we our only other current draws were recharging phones and running computers (on 12VDC) while at anchor.

There are threads about CPAP use on cruising boats on the following website (and the search function is easy to use):


I found the site very helpful, and the folks at SecondWind were wonderful. Their customer service is unparalleled. As to costs, I think I paid about $400 for a (then) state of the art auto-titrating CPAP. And all I did was plug it in - easy. Don't know what your all-in costs would be on the inverter and install, but for me, the decision was easy. Of course, it helped that I needed a new CPAP, mine was 8 years old at the time. I didn't involve my medical insurance, just paid out of pocket. Cheaper and quicker.

If I can help in any way, send me a PM and give me a day or so to respond, as I am out of the country.
Terrific advise! I should have posted here first before I tried to go my own way on this.
Thanks so much and will look into that machine. Is it quiet?
 

SFS

.
Aug 18, 2015
1,979
West Marine Kayak Tampa Bay
@Ilanortho - It is very quiet, even compared to my old one. That's one of the reasons it was recommended by the folks at SecondWind. I spoke with the owner, and it is the machine he uses. He answered lots of technical questions for me, knew the 12V cord was much cheaper than others, and checked the manual for the tech specs on current draw.

As someone mentioned above, you can't run the humidifier without drawing a lot more current. And if the machine can't go close to the berth, then longer hoses are easier to find than longer 12V cables.

Happy to answer other questions as they come up.
 
Jan 20, 2020
7
Hunter H336 Milwaukee
I use a Resmed Airmini when i travel. I have used it on many international trips and on the plane, i havent used it on the boat yet but a battery pack is available that i would charge by day use by night. The Airmini has a unique humidifier system called HumidX. Which recycles the moisture in your breath and mean you dont have to use extra power or go searching for distilled water
 
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Nov 26, 2012
1,536
Hunter 34 Berkeley
Mine, as I suspect yours is as well, is actually a 12 V machine that uses a converter in the power chord to plug into A/C power. You can get the plug that allows you to plug into 12V DC. That is what I did. Works great.
 
Jan 19, 2010
10,029
Hunter 26 Charleston
There was a guy on here about 3 years ago who posted a very nice thread about how he hooked up a small honda generator just for his CPAP. You might want to search the archives and see if you can find it.
 
Apr 8, 2011
471
Hunter 36 Deale, MD
I leave an older CPAP on the boat, which has a direct 12v plug. I don't recall what it draws, but it doesn't make a significant impact on my 400ah bank to worry about. I have used it on other occasions with a 50,000mah battery which has a 12v output option, and it will run for roughly 3 nights without needing a recharge. They're inexpensive. The battery is now too big to fly with (due to airline restrictions - not the size of the battery), but its a great option if the boat you're on is electrically challenged - I typically use the battery for car camping these days. Agree with others to ditch the humidifier. Also, be aware that the tubing, mask and filter(s) will fairly quickly pick up any "boat smells", so you'll want to change those out regularly.
 
Nov 22, 2011
981
Ericson 26-2 San Pedro, CA
I just got back from a 12-day trip to Catalina. I used my APAP machine every night. I have a single Group 31 battery for my house loads and a 100-watt solar panel. (I have a second battery I hold in reserve for engine cranking but did not use it for running the APAP or anything else.) I do not have refrigeration. The only significant loads I have are charging a laptop (which I used a great deal, working on writing projects), lights, my phone/hot spot, and the APAP. I had absolutely no problem keeping up with the loads. I had a mixture of cloudy, sunny, and partly cloudy days. I did not run the humidifier. (Personally, I prefer not to run it anyway.) I did not and have not observed picking up any "boat smells" while using this unit. My machine is an ResMed AirSense 10.
 
Oct 21, 2021
1
Beneteau 38 Emeryville Marina
Anyone who uses a C-pap have experience with chartering a boat in the Caribbean ??
Will be chartering a Moorings 35ft Cat -- my Resmed AirSense 10 uses 24volt DC (120V Trnsformer output 24v DC)
Hoping the boat has at least a 12volt DC output for at night --which would still require a step up device to deliver the 24v DC
 
Oct 22, 2014
16,148
CAL 35 Cruiser moored EVERETT WA
@GerdtheBird, we chartered a Catamaran from Moorings in Belize. One of us has a CPAP. 12VDC. We ran the generator during the evenings as the AC was needed. Fortunately we were in isolated anchorages and the generator was well muffled. The system provided 120 V AC. He simply plugged into the AC outlet.

I would take the hardware to convert the 12VDC to 24VDC in your case.
 
Dec 28, 2015
1,357
Laser, Hunter H30 Cherubini Tacoma
I would think a cat at that size( or any) would have at least a 1000 watt inverter. I run two Cpaps, one with and one without the humidifier going. On a 1000 watt with no issues.