How to power a cpap machine on a boat?

[BozSail]

I've recently been told by my doctor that I have fairly severe sleep apnea and have to use a cpap machine while sleeping. The machine runs on 110 voltage. What is the most efficient way to power this for eight hours a night when not hooked to shore power? I currently have 200 watts of solar and 390 watts for house bank. On reasonably sunny days, my power needs are generally met when anchoring. I'm concerned about the extra draw overnight from the cpap machine. Does anyone have experience with this?

[AnglaisInHull]

No personal experience or knowledge, but a friend has a CPAP that runs on 12 volts that he uses on his boat.

[Dockhead]

No experience, but it's a simple math problem. You need to know the total overnight consumption in watt/hours and compare that to power available overnight in your batteries. Power the machine through an inverter.

I would think that this could be easily handled by the average cruising boat's batteries, provided they are reasonably charged up. But you need to do the math. To get real life overnight consumption, you might want to do measurements using a Kill A Watt etc. device, at home.

[Dockhead]

This resource: https://www.google.com/url?sa=t&sour...gYL8gKwswDtgBd

says the average CPAP machine uses 30-60 watts on average. If it's 60 watts, then x 8 hours is half a kWH only. A small 400AH 12v bank has about 2.4kWH of useful power. Even allowing for the inverter, that's only 20% or so of available capacity.

But you should do your own measurements and calculations.

[donradcliffe]

There is a big difference in power consumption between the basic CPAP and one with the heaters/humidifiers turned on. Our experience is that you don't need a humidifier on a boat, and my wife's nightly power consumption is 15 amp-hours on a 120v machine connected through a small inverter. It draws less than the refrigerator.

The cpap keeps the wife from snoring. I would have her use it even if it took ten times the power.

[chubby]

Originally Posted by BozSail

I've recently been told by my doctor that I have fairly severe sleep apnea and have to use a cpap machine while sleeping. The machine runs on 110 voltage. What is the most efficient way to power this for eight hours a night when not hooked to shore power? I currently have 200 watts of solar and 390 watts for house bank. On reasonably sunny days, my power needs are generally met when anchoring. I'm concerned about the extra draw overnight from the cpap machine. Does anyone have experience with this?

why not just get a portable or 12V cpap machine?

[Adelie]

I have a CPAP. The 100v AC is converted to 12v-DC by a plug-in box before it enters the machine.

I haven’t tried to use directly powered by battery.

When we go car camping we have a little 165W inverter running off a 100Ahr deep cycle. Runs 2 CPAPs for a couple 3 days.

I measured energy use for 1 CPAP at home, 7hr night was 35Whr with the heater on.

[kayakerChuck]

We have a 12v CPAP for the admiral and a decent size power brick. The brick will power the CPAP for a little more than 2 nights, which gives us a bit of flexibility recharging it.

[Jammer]

Originally Posted by BozSail

Does anyone have experience with this?

Yes. The admiral uses a CPAP and will not sleep without it.

Recently I have persuaded her to purchase a travel CPAP. This is what we use aboard. It is much more compact, and instead of the humidification reservoir it has some sort of absorbent bead system that collects moisture from exhaled air and uses it to humidify inhaled air. The bead cartridge has to be replaced every few days but they are small and inexpensive.

I highly recommend purchasing a travel CPAP, if funds will allow.

You want to avoid faffing around with water reservoirs at all costs, because of the hassle, the need for distilled water, the power consumption, the space, the problems with keeping it upright, and the need for a heated hose with its own power consumption.

I now use the 175 watt Milwaukee "top off" inverter to run her CPAP on the boat. I use Milwaukee power tools and have plenty of batteries for them. She can get at least two nights out of an 8 amp-hour pack. In practice I charge the batteries next time I have shore power but there are 12v/24v DC chargers availalble.

I would guess it's 50 watt-hours a night.

Using the self-contained inverter means no cords, no special wiring, no concern about the effect on the boat electrical system, etc. Convenient and easy to manage.

Previously on a rented boat with her "big" CPAP I ran it off a group 24 FLA (1000 watt hours) and an expensive dedicated 12v power supply from the CPAP maker, and it ran for a week. She was using the humidifier but had it on a low setting. The battery died the last night, so probably 150 watt hours a night.

The humidifier, and heated hose if present, draw a great deal of power depending an ambient temperature and machine settings. Hundreds of watt hours a night

For most CPAPs there's a mobile/aircraft power supply, and for many there's a self-contained lithium battery option. These are always expensive options and are specific to a particular make and model, so when the CPAP ultimately and inevitably fails, these parts are worthless.

[garyfdl]

I see this being advertised a lot lately. Might be worth checking out/asking your Dr. about.

https://www.inspiresleep.com/?gclid=...4aAoxOEALw_wcB

[psk125]

A 12-volt transformer is available for my C-Pap machine. It plugs into a cigarette lighter fixture. Check to see if yours doesn't have one too. If you get the right kind, they also work in Europe so long as you have the right plug.

[Half-Blind]

I use a CPAP. They are actually 12V or 24V. IF yours is 12, wire in a cigarette lighter adapter off of your 12 volt system. If 24, wire in a cig adapter, they use a 12 volt inverter to power from that. Turn off the tube heater, it will work fine.

[paralog]

Originally Posted by BozSail

I've recently been told by my doctor that I have fairly severe sleep apnea and have to use a cpap machine while sleeping. The machine runs on 110 voltage. What is the most efficient way to power this for eight hours a night when not hooked to shore power? I currently have 200 watts of solar and 390 watts for house bank. On reasonably sunny days, my power needs are generally met when anchoring. I'm concerned about the extra draw overnight from the cpap machine. Does anyone have experience with this?

Hi, Turn off the heat function first as that draws amps. You can purchase a 12 volt adapter for most of the models. I use mine with a small inverter and have never had a problem with battery power but i do use my engine quite a lot here on the PNW coast.

[JPA Cate]

I, too, have been diagnosed with severe sleep apnea. I know there's a lot of scary stuff published about it, too, which I largely ignore. My CPAP machine plugs into a cigarette lighter socket, just beside the berth. It was a hassle, but Jim managed to run the wires for it. It is the heater and humidifier that cost the most electricity. I hate wearing the headgear, but it did return me to a good energy level. As a result, I usually snatch it off around 0400.

In my case, I have also been doing respiratory therapy, exercise, and have lost weight, and my apnea symptoms have been dwindling. Ymmv. I haven't used my machine, since October, now, but it is there if I start needing it.

I'm sure Jim would answer if you send him a PM about the data for the consumption. We were able to bear it in the southern hemisphere summer, but expected to need more than just our solar for it in the low sun angles and lower hours available in winter.

Ann

[PirateFoxy]

Originally Posted by JPA Cate

IIn my case, I have also been doing respiratory therapy, exercise, and have lost weight, and my apnea symptoms have been dwindling. Ymmv. I haven't used my machine, since October, now, but it is there if I start needing it.

Watch out for allergens, too. I have trouble when my allergies are bad, otherwise I'm fine. In the house I run a Corsi-Rosenthal box (like people have been making for Covid) in the bedroom as I find it's more effective and quieter (with a good fan) than the air cleaner we have even though it's supposedly sized correctly for the room. We are going to experiment with a smaller sized one for the RV - I have 10" filters and also 10x20", but we're not sure which fan will be best - 10" plug in running off the RV batteries, or a 10" battery power fan that can run by itself overnight and be charged during the day when the solar is functional. We may also experiment with computer case-type fans to try to get something that is effective but as quiet as possible.

I have trouble sleeping with the whole mask and tube thing so the CR box results in much better quality sleep for me than a CPAP.