Canping questions

[Gary_UT]

I am a new CPAP user, first use December 28the 2013.

We do a lot of camping in our travel trailer, I have a 12V cord to run the CPAP in the trailer. In the hottest months we camp at higher elevations to get out of the heat, 8000-9500 feet.

My CPAP manual (460P) says it will automatically compensate for altitude, but it lists 7500 feet as the max.

Will the machine work at higher altitudes?

Also, is it better to run the CPAP machine from the trailer battery's or use a separate battery pack?

Gary

[Pugsy]

The machine will work/function/blow air at elevations higher than 7500. It just can't make the auto adjustments for altitude.
It will be really close to accurate in terms of what pressure gets used. It's not like you will get only 50% of setting.

I will let someone else cover the battery question.
How long do you normally camp? Weekend 2 or 3 days or week long?
Will you be where you can recharge whichever battery you do use during the day?
Are you going to want/need to use your humidifier? The humidifier is a big energy hog.

For me I would want the battery that JohnO used and reported on in this thread.
I think his comments start around page 3 of the thread.
viewtopic.php?f=1&t=86960&st=0&sk=t&sd=a&hilit=battery
The reason I would want that battery...because he got multiple nights with using the humidifier with it and I wouldn't want to go without my humidifier. And if I went camping I would end up somewhere without power to recharge batteries in vehicle/trailer or whatever.

[CapnLoki]

Also, is it better to run the CPAP machine from the trailer battery's or use a separate battery pack?

If by "trailer battery" you mean a starter type battery, then no, don't use that. Make sure your starter battery is only used to start the engine! But if its a deep cycle RV or marine type battery, setup to run lights, TVs, and other modern conveniences, then it will be OK. If you don't run a humidifier, and you run an average pressure of 10, you'd use about 8 Amp-hours or less, roughly the same as a small TV or laptop for a few hours, generally within the capacity of an RV battery that's getting charged daily. If you run the humidifier however, it depends on a lot of variables, and it could mean up to 30 additional Amp-hours and now you would think about adding an extra battery. Normally campers have enough ambient humidity to go without the humidifier, but at 8000 feet it could be pretty dry! If you plan to go several days before recharging, then you need to do the math, add in a goodly safety margin, and size accordingly.

Here's ResMed's guide to battery use, Respironics should be similar, if not more efficient:
http://www.resmed.com/assets/documents/ ... lo_eng.pdf

[CowFish]

My CPAP manual (460P) says it will automatically compensate for altitude, but it lists 7500 feet as the max.

Will the machine work at higher altitudes?

What are your pressure settings?

[Gary_UT]

CapnLoki: the trailer has 2 6V deep cycle batteries wired in series for 12V.

CowFish: I am using a pressure setting of 16.

Gary

[sleepy guesty]

CapnLoki: the trailer has 2 6V deep cycle batteries wired in series for 12V.

CowFish: I am using a pressure setting of 16.

Gary

i think it would be prudent to add a 12v battery + outlet
just for your cpap
if you know how
if you dont know how contract out
it should be charged daily
make it as big as you budget can handle
you wont be sorry or leave the other things w/o power

[Sia]

The S9 series have several pressure sensors.
A pair is used in a differencial way to measure the pressure in the out path. Being differential, it focuses only on the difference from one sensor to the other.
It adjusts the (pump) motor so that that difference is the pressure it needs to pump out.

Think of it like the "zero" function of scales. The S9 zeors in on your current altitude and adds the needed pressure on top of that. And it does so constantly.

This works up until the air is too thin of course, which is close to the end of the troposphere.

http://en.wikipedia.org/wiki/Earth%27s_ ... pal_layers

So unless you go on a high altitude baloon to the border of space, you'll be fine.

[CapnLoki]

the trailer has 2 6V deep cycle batteries wired in series for 12V.

Good. The most common 6V deep cycles are "golf cart" batteries; the most common high quality version being the Trojan T-105, but all the major manufacturers have a version. Two of them can hold 225 Amp-hours at 12V. They will give hundreds of deep cycles if not discharged below 50%, and while a good car alternator can get them back to 85% in a couple of hours, the last bit takes more extended charging. Thus, its common to cycle between 50% and 85% charged, meaning the useful capacity is 35%, or in this case 78 Amp-hours.

So, now the question is how are you going to use this? With full humidity, it might only last two days, but without maybe a week. (Your higher pressure still probably under 10 amp-hours/night.) And what else are you powering in the trailer? A few lights and a radio for an hour before bedtime won't add a lot, but a TV and computer can. And if you're running a major appliance, like a fridge, you're already taxing the system. You have to do the math, and if it works out that you need more power, the most expedient way is to double your existing setup so that all the batteries are the same. (You can parallel in two more golf cart bats, but you need some big cables.)

And how do you recharge? For fast charging this can accept about 35-50 Amps, but I'm not sure what a car/small truck puts out at idle - it depends on the regulator settings. A small genset (1000 watts or more) will work, but you might need to use the 120v output through a charger, rather than the 12v output which is often 10amps or less. Of course the easy way is to pull into a campsite with a power cord every few days.

BTW, most summers I live for a month or two on a boat, on a mooring, off-grid. We have 4 golf cart batteries (450 Amp-hours total) plus two starting batteries. We run a small fridge, TV, radio, several computers, and a host of other things from tooth brushes to a coffee grinder (one must not sacrifice coffee quality!). Charging is mainly with a high output alternator on a diesel engine, but we also have a small genset and 3 solar panels. I've been obsessive on cutting back use, so while we use a lot of gadgets, the total load has come down, helped by led lights and tablet computers, etc.

[ChicagoGranny]

I am a new CPAP user, first use December 28the 2013.

We do a lot of camping in our travel trailer, I have a 12V cord to run the CPAP in the trailer. In the hottest months we camp at higher elevations to get out of the heat, 8000-9500 feet.

My CPAP manual (460P) says it will automatically compensate for altitude, but it lists 7500 feet as the max.

Will the machine work at higher altitudes?

Also, is it better to run the CPAP machine from the trailer battery's or use a separate battery pack?

Gary

Do you keep up with your data to know how effective the therapy is currently? At what elevation are you now using CPAP?

16 cm is a high pressure. Is there a chance you could sleep for one night at max elevation (9500 ft.) just to see how you do? I would not want to make a 3-week commitment at 9500 ft and then find out I don't feel well the entire time.

ChicagoGramps

[Gary_UT]

Do you keep up with your data to know how effective the therapy is currently? At what elevation are you now using CPAP?

16 cm is a high pressure. Is there a chance you could sleep for one night at max elevation (9500 ft.) just to see how you do? I would not want to make a 3-week commitment at 9500 ft and then find out I don't feel well the entire time.

ChicagoGramps

Our house is at 4300 feet, my AHI has averaged .77 since I started using CPAP 49 days ago.

I will try an overnight trip to higher altitudes once it warms up here.

Gary

[ChicagoGranny]

my AHI has averaged .77

I will try an overnight trip to higher altitudes once it warms up here.

ChicagoGramps