CPAP machines in 2020 - I need your expertise!

[chrisMills]

TL;DR: have sleep apnea, need a CPAP machine to breathe at night; what are the ramifications of needing a CPAP machine on a 57ft narrowboat? A 12V/24V car-style adaptor is available which I understand is more efficient than the AC adaptor I currently have. Should we be looking at extra batteries or solar panels or something? We will harbour during winter months. Comments welcome. 
 

Me and my husband have decided to live on a narrowboat full time next year. As the subject suggests, my silly brain decides to stop operating my phrenic nerve dozens of times an hour when I’m asleep, and since I wish to live on a narrowboat with my husband shortly, the use of a CPAP (Continuous Positive Airway Pressure) machine is a deal breaker, because I like breathing when I’m sleeping.

 

My machine is a ResMed AirSense 10 Autoset and they do a car adaptor for it which is classed as 12/24V. It provides a DC to the machine. It has a car-like plug. 

 

So... ...for those who also need one of these fantastic devices to stay out of health problems, is there anything I need to be aware of before committing to a floaty lifestyle?

 

[GUMPY]

You will need to look at how much current they consume, whether the batteries on the boat can supply it and how you will recharge the batteries.

[WotEver]

4 minutes ago, Loddon said:

You will need to look at how much current they consume, whether the batteries on the boat can supply it and how you will recharge the batteries.

The spec states that it draws 1-1.5A at 110-230V AC and that no DC option is available, which doesn’t help us much. 
 

9 minutes ago, chrisMills said:

they do a car adaptor for it which is classed as 12/24V. It provides a DC to the machine. It has a car-like plug. 

Does this have a model number, or can you give us a link to it?

[GUMPY]

Spec;

 

DC output:
24V 
3.75A
Typical power consumption:
53W (57VA)
Peak power consumption:
104W (108VA)

--------------------------

3.75A at 24V so 7.5A at 12v  depending on how long it needs to be on for that will be a fair hit on the batteries.

[chrisMills]

 Thank you both for your kind replies.
 

I sleep 8 hours per 24 hour period. 
 

Here is the link to the machine. And here is the link to the adaptor.

 

[GUMPY]

To run that off boat batteries will be a big ask. Its to late in the day for me to do figures but roughly you will have to double the battery capacity on most boats ( 8 instead of 4) to make it usable.

 

 

 

[WotEver]

32 minutes ago, chrisMills said:

here is the link to the adaptor.

Okay, that states a peak consumption of 110W, with 70W being ‘typical’. 8A at 12V gives 96A (the voltage would normally be above 12V so that gives some margin for error). 8A for 8 hrs = 64Ah, which is the total usable capacity of a 120Ah battery. As Loddon states above, that’s a very large draw; something like three times what you’d expect a fridge to use in 24 hours. To decide how large a battery bank you’d need to power the device you absolutely must do a power audit of all I your other items. 
 

I believe your biggest problem will be in generating the power daily to replace what you use in each 24 hour period, particularly in the winter when even a large solar setup cannot be relied upon. If you’re intending to be based in a marina or other mooring with mains power then it won’t be as much of a worry. 
 

Please come back with your audit calculations along with whether you’re planning on being marina based or continuously cruising. 
 

@Tony Brooks has some information to assist you with carrying out an audit here:

http://www.tb-training.co.uk/MarineE05.html#The power audit

[BEngo]

I know a couple who live aboard and he relies on CPAP pretty much 24/7.  They cruise  regularly  off grid, and have mains and 12V  concentrators.  Power for the 12 V machine is a consistent problem (notwithstanding they have a roof full of solar and a quite large battery bank) and as a result he relies more on cylinders.  There is apparently a good system for delivering full cylinders but the one for taking away empties is carp so when they return to base they have to organise a mega offload to various suppliers.

 

Oxygen on board is also an apparent H&S/insurance nightmare over things like SF stoves and gas cookers ( naked flames)

 

PM me your details and I will see if they are willing to talk direct.

N

 

[jpcdriver]

I use a Resmed Escape S8 with humidifier on my narrowboat. I was concerned about battery capacity when buying the boat but in the end the boat we bought only had 3 110Ahr batteries. I'm running it off AC via a Victron inverter. In practice it has not been a problem. The humidifer is the main issue as it effectively is warming water, but I only run it at a fairly low level. If you are not using a humidifier I don't think you will have any issues. I was being fairly careful with power use and reckoned that the CPAP machine and fridge used about 15% of my battery capacity overnight. However the batteries seemed to start deteriorating quite quickly after 2 years. I have replaced with 3 100Ah (@C10) Leoch Lead Carbon batteries. These seem to be standng up better to my usage and charge much quicker than the previous batteries.

 

I think the ResMed AirSense 10 is a more sophisticated machine than mine and will 'throttle back' and use less air pressure and hence energy when it can.

 

(For those doing the calculations, I don't doubt it but in practice those consumptions have not been my experience.)

 

May I add that if anyone has a partner that says 'you snore really bad and stop breathing at times' do get it checked out. Under tests I stopped breathing ON AVERAGE 59 times per hour over one night (that is not breath for at least 10 seconds). This was linked to optic nerve damage in one eye which thankfully was recovered but I count myself lucky. The other risks of sleep apnoea are stroke and heart attack!

[Guest]

/\/\/\

 

Good post.

[WotEver]

28 minutes ago, jpcdriver said:

For those doing the calculations, I don't doubt it but in practice those consumptions have not been my experience.

Good to know. I hate doing calculations based on published specs as opposed to real world experience. Do you have any actual figures for consumption?

[jpcdriver]

To the OP - do you know what level your machine is set at? I'm set at 20 cm H2O, but if yours is set much higher then I would expect a higher power usage, which is possibly why the stated specs are somewhat higher to that which I have experienced. 

[jpcdriver]

5 minutes ago, WotEver said:

Good to know. I hate doing calculations based on published specs as opposed to real world experience. Do you have any actual figures for consumption?

I do have an electricity monitor on my house electrics and did think about trying to get a proper measurement of consumption. However, by the time the machine has settled into its typical consumption mode (it 'ramps up over the first 5 - 20 mins depending on setting) I'm hooked up to the machine by a 2m hose and asleep. ?

[transplant]

You can save a lot of power by not using the humidifier/heated hose but based on what I've read of people running their CPAPs on portable batteries I don't think it'll be an issue so long as you're able to top the batteries off during the days (so solar in the summer, marina hookup or engine usage in winter).

 

If you can't measure a night's power usage take a look at some of the camping forums to see what people are powering theirs with, some people are reporting several days usage off of a regular deep-cycle battery.

Edited September 12, 2020 by transplant

[chrisMills]

On 11/09/2020 at 22:39, jpcdriver said:

To the OP - do you know what level your machine is set at? I'm set at 20 cm H2O, but if yours is set much higher then I would expect a higher power usage, which is possibly why the stated specs are somewhat higher to that which I have experienced. 

It is set remotely by the doctor over 3G but isn’t anything like as strong as it goes. It goes between 4 and 12 cmH2O but I’m not sure what average to be honest. 

[jpcdriver]

14 hours ago, chrisMills said:

It is set remotely by the doctor over 3G but isn’t anything like as strong as it goes. It goes between 4 and 12 cmH2O but I’m not sure what average to be honest. 

That is a lower setting than mine so I think the power consumption should be less.

 

I would say go for it and don't worry too much. A boat with 4 or 5 leisure batteries would be good but it can be done with 3.