Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-07-2019, 02:35 PM   #1
Guru
 
HopCar's Avatar
 
City: Miami Florida
Vessel Name: Possum
Vessel Model: Ellis 28
Join Date: Aug 2011
Posts: 5,299
CPAP on board

I use a CPAP machine when I sleep. I going on a houseboat cruise to Whitewater Bay next week for two nights. There is no generator on the boat.

The machine draws 1.5 amps of 110 volts to run. I have a 300 watt pure sine wave inverter.

Any suggestions on how to power this thing?
__________________
Parks Masterson
Retired from Hopkins-Carter Marine Supply
HopCar is offline   Reply With Quote
Old 12-07-2019, 03:08 PM   #2
Guru
 
Xsbank's Avatar
 
City: Pender Harbour, BC
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,791
Mine has a 12 volt adapter because it runs on 12 volts with a transformer. Are you sure it runs on 120? You can probably turn off the humidifier for lower draw too.

Not a complete answer but maybe there is some wheat in my chaff.
__________________
Don't believe everything that you think.
Xsbank is offline   Reply With Quote
Old 12-07-2019, 03:15 PM   #3
Guru
 
LarryM's Avatar
 
City: League City, TX
Vessel Name: Pelago
Vessel Model: Wellcraft 3300 Coastal
Join Date: Aug 2011
Posts: 1,069
Quote:
Originally Posted by HopCar View Post
I use a CPAP machine when I sleep. I going on a houseboat cruise to Whitewater Bay next week for two nights. There is no generator on the boat.

The machine draws 1.5 amps of 110 volts to run. I have a 300 watt pure sine wave inverter.

Any suggestions on how to power this thing?
If the houseboat has a 12VDC cigarette lighter plug, you could purchase the accessory 12V travel adaptor from the CPAP machine manufacturer and power it that way. Most machines I've seen have that option. No inverter efficiency losses that way either.

Come to think about it, you could also power your 300 watt inverter the same way if the lighter socket has enough capacity.
__________________
Larry
M/V Pelago
LarryM is offline   Reply With Quote
Old 12-07-2019, 03:16 PM   #4
Valued Technical Contributor
 
DavidM's Avatar
 
City: Litchfield, Ct
Join Date: Aug 2012
Posts: 6,775
Well given the specs you quoted, the inverter should power your CPAP ok. But I don't know if the boat's DC system can handle it. The CPAP draws 1.5 amps A/C which means about 17-18 amps DC to the inverter (small pure sine wave inverters aren't very efficient. That will mean about 135 Ahs of use in an 8 hour period.

With no other DC loads (unlikely) you will need about 250 Ahs of battery capacity, plus you will need a way to recharge those 135 Ahs. If you move the next day then maybe the propulsion engine will have enough power to recharge them. Otherwise the battery must be much bigger.

So you need to check on the battery capacity of the houseboat and how it can be recharged the next day. Also how to plug into DC. A cigarette lighter outlet might work, but 17 amps is usually beyond its typical 15 A breaker supply.

David
DavidM is offline   Reply With Quote
Old 12-07-2019, 03:18 PM   #5
Guru
 
oscar's Avatar
 
City: Bethlehem, PA
Vessel Name: Lady Kay V
Vessel Model: 1978 Hatteras 53MY
Join Date: Oct 2015
Posts: 1,098
Quote:
Originally Posted by HopCar View Post
I use a CPAP machine when I sleep. I going on a houseboat cruise to Whitewater Bay next week for two nights. There is no generator on the boat.

The machine draws 1.5 amps of 110 volts to run. I have a 300 watt pure sine wave inverter.

Any suggestions on how to power this thing?
Well, assuming you can obtain enough length of wire with a few spring clips on one end (adapting a cheap set of jumper cables has been done) and you can get to the batteries here's the math:

110VAC*1.5AhAC=165W/12VDC=13.75AhDC.... Round it up to 14 and add some for the parasitic load of the inverter, let's call it an even 20A.

So if said house boat has a house bank of 400Ah you can safely take a 10 hour nap.
__________________
https://ladykay.blog/
oscar is offline   Reply With Quote
Old 12-07-2019, 03:21 PM   #6
Senior Member
 
fractalphreak's Avatar
 
City: La Conner WA
Vessel Name: Northwest Dream
Vessel Model: Davis Vashon 42 Trawler (Defever design)
Join Date: Jun 2018
Posts: 318
If you figure our the wattage requirements for your 1.5 amp draw, that 300 watt inverter will work, but....you'd have to wire that thing into the boat system somehow.

Check for a 12v power supply for your cpap. Many of them have them available as an extra purchase item....If available, see if your houseboat will have a suitable 12v receptacle in your berth.

CPAP, like a lot of electronics, are DC inside, so that AC plug is another power supply that adds some to your power loss getting the thing to run...

That will at least get you using the boat native 12v system without inverter losses. The next thing is making sure the houseboat has enough amp hours for your stay...based on the 1.5 amp at 120v requirement, your CPAP will probably be drawing around 170-180 watts max (you will likely find it closer to 170 or less once you are powering from straight DC) which will end up being something like 14-15 amps...

The boat will need that X how many hours you sleep in amp hour capacity to run your CPAP. If you are sleeping 8 hrs a night you'll be using up 120 aH or so....On NWD my CPAP is a larger daily aH draw than our full sized Vitrifrigo refrigerator.

If the boat doesn't have that power, you might think of something so radical as taking a deep cycle battery with you and your inverter...I still suggest the 12V power supply for your boat, it really does help cut down some of the power requirements.
__________________
"There exist minds that think as well as you do, but differently."
fractalphreak is offline   Reply With Quote
Old 12-07-2019, 04:38 PM   #7
Guru
 
tiltrider1's Avatar
 
City: Seattle
Vessel Name: AZZURRA
Vessel Model: Ocean Alexander 54
Join Date: Aug 2017
Posts: 4,281
You can buy battery operated travel size Cpap machines. Cpap is something you use everyday for 6+ hours. If there is any aspect of your life you should invest top dollar in, its your Cpap collection.
tiltrider1 is offline   Reply With Quote
Old 12-07-2019, 04:54 PM   #8
Guru
 
City: Boston
Vessel Name: Adelante
Vessel Model: IG 30
Join Date: Nov 2016
Posts: 1,608
Houseboat may have 120V inverter already installed. Check on battery capacity and recharge capacity. (Need to determine how long engine will be run and at what speed. Alternator's don't put out max amperage until they are at max rpm.)

You could buy a portable Li-ion battery that will give you overnight capacity, but of course that will need 120V to be recharged during the day.

(Edit: Honda 2000 would be a viable solution)
SoWhat is offline   Reply With Quote
Old 12-07-2019, 05:07 PM   #9
Guru
 
HopCar's Avatar
 
City: Miami Florida
Vessel Name: Possum
Vessel Model: Ellis 28
Join Date: Aug 2011
Posts: 5,299
Thanks guys! Great feed back. My math seems about the same as yours. I need to know more about the house boat. I’m not even sure how it’s powered, probably outboard. I do have a Honda 2000 generator. Might have to bring that along.

The machine actually runs on 24 volts. The power supply says input 110 volts 1-1.5 amps, output 24 volts 3.75 amps. It also says 90 watts next to the output cable.
__________________
Parks Masterson
Retired from Hopkins-Carter Marine Supply
HopCar is offline   Reply With Quote
Old 12-07-2019, 05:18 PM   #10
JLD
Guru
 
City: Delaware
Join Date: Mar 2017
Posts: 681
I bought a Goal Zero Sherpa 100AC, before I went to Puerto Rico a couple of years ago, right after Hurricane Maria.

I have an older ResMed CPAP unit and I don't use the humidifier. I can get 2 full nights with the battery, although I have to admit that the pressure for my CPAP is pretty low.

Here is the newest version of the Goal Zero Sherpa:



I like my older Sherpa. Its the largest portable battery that I can carry-on an airplane.

I paid $300 for mine a couple of years ago. I see that Goal zero has the new version on sale for $240 from $300.

Jim
JLD is offline   Reply With Quote
Old 12-07-2019, 05:44 PM   #11
JLD
Guru
 
City: Delaware
Join Date: Mar 2017
Posts: 681
Sorry, the new version of the Goal Zero may not work for the CPAP.

The old version had a 12V outlet at the back that I could use with the Goal zero supplied cable that I could then plug into the cigarette lighter adapter (brick) that I purchased separately from ResMed.

The new version of the Sherpa has a USB-C for DC output, something you may not have with the CPAP machine (I still use my ResMed from 2012).

You don't want to use the AC output from a battery as would be inefficient with the conversion from DC to AC to DC. Although this might still be enough to last one night.

Jim
JLD is offline   Reply With Quote
Old 12-07-2019, 05:51 PM   #12
JLD
Guru
 
City: Delaware
Join Date: Mar 2017
Posts: 681
I have the same numbers on the brick of my ResMed CPAP.

I confess that I don't know much, but I think this is the maximum power draw on my CPAP when using the humidifier (which consumes a lot of power).

I was concerned when I purchased my battery that it wouldn't last, but I had read on one of the CPAP forums, at the time, that a CPAP machine with low pressure would last significantly longer than one running at a higher pressure AND using the humidifier.

Jim
JLD is offline   Reply With Quote
Old 12-07-2019, 06:25 PM   #13
Senior Member
 
fractalphreak's Avatar
 
City: La Conner WA
Vessel Name: Northwest Dream
Vessel Model: Davis Vashon 42 Trawler (Defever design)
Join Date: Jun 2018
Posts: 318
Going without the humidifier is a good point. I don't, so my power use is high; I've never tried computing what it would be without...I agree that would be a significant drop, assuming you can do that.

Good input here from a lot of folks. I have used CPAP for over 10 years, but only recently discovered CPAP forums and only recently came up with having a dedicated multiple machines for different uses. Right now my meger collection is the newest fanciest big brother machine that phones in my data at home, and the old tried and true machine out on the boat always ready to go, so I never have to take that contraption out there.
__________________
"There exist minds that think as well as you do, but differently."
fractalphreak is offline   Reply With Quote
Old 12-07-2019, 06:58 PM   #14
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Vessel Name: Carquinez Coot
Vessel Model: penultimate Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 12,559
My gawd. I'd rather have open-heart surgery (done that) than be a slave of CPAP.
__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 12-07-2019, 07:16 PM   #15
Guru
 
C lectric's Avatar
 
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,409
Quote:
Originally Posted by markpierce View Post
My gawd. I'd rather have open-heart surgery (done that) than be a slave of CPAP.
Where'd that come from?

I haven't had either problem but people do what they have to do. I've known several people that needed a CPAP aboard and they do just fine, just with some adjustment in the lifestyle.
C lectric is offline   Reply With Quote
Old 12-07-2019, 07:30 PM   #16
Guru
 
tiltrider1's Avatar
 
City: Seattle
Vessel Name: AZZURRA
Vessel Model: Ocean Alexander 54
Join Date: Aug 2017
Posts: 4,281
Quote:
Originally Posted by markpierce View Post
My gawd. I'd rather have open-heart surgery (done that) than be a slave of CPAP.
Ignorant response. No one chooses medical conditions and I doubt HopCar would trade Sleep Apnea for a pace maker.

Here is a battery solution for all Cpap’s
https://www.cpap.com/productpage/por...t-cpap-battery
tiltrider1 is offline   Reply With Quote
Old 12-07-2019, 07:40 PM   #17
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Vessel Name: Carquinez Coot
Vessel Model: penultimate Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 12,559
Quote:
Originally Posted by C lectric View Post
Where'd that come from?

I haven't had either problem but people do what they have to do. I've known several people that needed a CPAP aboard and they do just fine, just with some adjustment in the lifestyle.
Yes, probably a life-time bother while heart surgery doesn't necessarily require a pacemaker.

Gee, my attempt to be sympathetic backfired.
__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 12-07-2019, 08:07 PM   #18
Guru
 
C lectric's Avatar
 
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,409
Mark, yeah I know what you mean. I've had several comments backfire and not just here. The intention is one thing, the effect is another.
C lectric is offline   Reply With Quote
Old 12-07-2019, 09:03 PM   #19
JLD
Guru
 
City: Delaware
Join Date: Mar 2017
Posts: 681
My suggestion would be that you consider buying a battery anyway, especially if you are dependent on the CPAP. My sleep apnea is mild, so I use my machine for better sleep and to prevent snoring (wife sleeps much better as well)!

If you sleep apnea is more severe then you probably should have a back-up battery for emergency use. Batteries don't have to be Li, but that is my personal choice. Goal Zero (and others) also sell 200W and 400W batteries. This is a more economically choice that buying a battery from the CPAP manufactures and you can also use a battery like the Goal Zero for other uses as well, I sometimes use my 100W battery for my computer.

The down side is that if you can fly with these larger batteries, but if you are driving to where the boat is, it doesn't matter.

Jim
JLD is offline   Reply With Quote
Old 12-07-2019, 10:03 PM   #20
Guru
 
Wayfarer's Avatar
 
City: Beaufort, NC USA
Vessel Name: Sylphide
Vessel Model: Kingston Aluminum Yacht 44' Custom
Join Date: Aug 2014
Posts: 2,228
It's weird. Sometimes It feels like a relief to have it, and sometimes it feels like a ball and chain. It can be a real pain, but I definitely need it. I run mine off the inverter when I'm away from shore power most of the time. I also have a couple of these batteries:

http://www.batterypowersolutions.net...m-cpap-battery

They're stupidly expensive, and I only get one night's sleep out of one, and that's without the humidifier, but they've saved my bacon before.

I got them for camping, and have used them several times with my recent house bank and charging issues.
__________________
Dave
Just be nice to each other, dammit.
The Adventures of Sylphide
Wayfarer is offline   Reply With Quote
Reply

Tags
cpap

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 01:20 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012