Solar panels and CPAP machines?

[FMLNM]

I have tried finding the answer by searching the forums but have not had much luck. We have the 90w solar panels plus 2 6v batteries installed by Escape. We find ourselves needing to run 2 CPAP machines (5amp each) and are wondering if we can do that on just battery power....no hookup available. We figure to run the machines about 7 hours a night. So I guess that would be 35amp hours per machine (7 hours times 5 amps).
We are in NM and will be camping in Utah and the weather is expected to be good so sunshine is not going to be an issue.

Can anyone help me figure out if that is feasible? If necessary we could run just 1 machine.

Thanks!

PS - We have the 1500w inverter.

[J Mac]

What is a CPAP machine?

[Sandra L]

Continuous Positive Airway Pressure is what CPAP stands for. It is used to help those with sleep apnea.

[jamman]

You have 232 amp hours if the batteries are fully charged. And they should not be run below 50%.

Assuming your 5 amp figure is for a 12V DC plug then you will use 2*5*7 = 70 amp hours. IF your 5 amp figure is for 120V there is no way you can run them.

If you have a 90 Watt panel you get at most 7+ amps, and much less when it is shaded or the sun is low, or it is cloudy, etc. Say you average 5 amps for 10 hours a day (which is probably optimistic).

Assuming no other power use (water pump, fridge control, smoke/LP detector, lights - an unrealistic assumption) you will be losing 20 amp hours per day and so you will need some additional power source. Another solar panel, a generator, ... And if you crank up the inverter you will really run down the batteries.

Day 1 end batteries = 232
Day 2 start batteries = 232-70=162
Day 2 end batteries = 162+50=212
Day 3 start batteries = 212-70=132
Day 3 end batteries = 132+50=182
Day 4 start batteries = 182-70=112 *** below 50%, not good

[jamman]

If you can get by with only 1 machine you are in MUCH better shape (power wise - don't know about health.) You can probably sustain that with 1 solar panel and some careful use of power. LED lights, water pump OK, NO inverter use, etc.

[Donna D.]

AND, like all technology... older CPAP machines require more power than the "newer" models. Be safe. But still, think how long you have owned the machine and it MAY be time to check out a newer model...

[Kærnehuset]

In relation to one CPAP machine only, you will be fine as the CPAP machine by itself, does not draw much power. I can't speak on two machines. But I recommend you do not use the humidifier attachment as that increase the draw significantly and you will drain the batteries down below true acceptable level overnight. The only time I use the humidifier is when we are hooked into shore power.

Regards

Scott

[hotfishtacos]

You may be able to plug directly into a 12 volt supply from the trailer. Draw power directly from the batteries at night which is most efficiant then let the solar re-charge the batteries during the day.

Read this:
http://www.resmed.com/assets/documen...de_glo_eng.pdf

[Devil Dog]

You may cosider a wind turbine they run day and night. They can be a little noisy at hi speeds. But very effective.

[Kærnehuset]

Yes, I forgot to add that you do need to get the proper 12 volt inverter for your specific CPAP machine that will plug into the 12 volt system in the trailer. It has a cigarette lighter style plug on it which can plug directly into the socket in your trailer.

Scott

[hotfishtacos]

Converter, not inverter...

Originally Posted by Kærnehuset

Yes, I forgot to add that you do need to get the proper 12 volt inverter for your specific CPAP machine that will plug into the 12 volt system in the trailer. It has a cigarette lighter style plug on it which can plug directly into the socket in your trailer.

Scott

[FMLNM]

Thanks for all the helpful suggestions and information.
To provide more information, both machines are new...3 months and 1 month each so they are newer models. (We both just starting using them so we have no experience with this trailer issue....) We would definitely not be running the humidifier options on either machine.
We would have to get a converter in order to plug into the cigarette lighter and run on 12v. But those cords are only 7 feet long and the cig outlet is under the dinette in the Escape...pretty far from the head of the bead in the loft.
If we stayed with the standard power we would have to use our inverter and run off the one outlet that is powered by it. They do make battery packs for these CPAP machines but they are quite pricey...we'll just have to think about it...maybe just one machine on the inverter and see how it draws the battery down for one night.

[tractors1]

I think I'd try to get 12V routed up to the bed area to use the simplicity of a converter vs inverter and/or dedicated batteries. Also keeps the floor area free of cords in the middle of the night.

Charlie Y

[escape artist]

Hi: FMLNM... This issue is why I elected to have a dental device rather than the CPAP machine. It's very portable, takes no power except hot water, but some getting used to!!!
As for a kiss goodnite... either way forget it!!! Alf
escape artist N.S. of Lake Erie

[paulw]

I use a Phillips Respironics auto CPAP in the trailer. It runs on 12v with an optional cord so I had an outlet installed near the overhead where it resides. I fill the humidifier reservoir but don't turn on the heat.
We mostly have electric hook ups, but have operated it for 4 nights on one trip with a just a portable 50w solar panel and didn't notice any significant low battery condition.

[FMLNM]

Originally Posted by paulw

I use a Phillips Respironics auto CPAP in the trailer. It runs on 12v with an optional cord so I had an outlet installed near the overhead where it resides. I fill the humidifier reservoir but don't turn on the heat.
We mostly have electric hook ups, but have operated it for 4 nights on one trip with a just a portable 50w solar panel and didn't notice any significant low battery condition.

That's great info! Ours are both Phillips Respironics auto cpaps too. Could we just tap into the lights in the loft to get that 12V supply?

[FMLNM]

Originally Posted by paulw

I use a Phillips Respironics auto CPAP in the trailer. It runs on 12v with an optional cord so I had an outlet installed near the overhead where it resides. I fill the humidifier reservoir but don't turn on the heat.
We mostly have electric hook ups, but have operated it for 4 nights on one trip with a just a portable 50w solar panel and didn't notice any significant low battery condition.

Do you remember which 12v cord system you used and where you bought it?

[paulw]

Originally Posted by FMLNM

Do you remember which 12v cord system you used and where you bought it?

Its a Phillips brand I got at CPAP.com (I've been very happy with their prices & service).
CPAP.com - Shielded DC Cord for PR System One 60 Series Machines
I see there is also a generic one listed for a number of brands.
You may have to send them a copy of your prescription if you want to buy machines or masks from them, but the cord should be a simple transaction.

[paulw]

Originally Posted by FMLNM

That's great info! Ours are both Phillips Respironics auto cpaps too. Could we just tap into the lights in the loft to get that 12V supply?

I'll leave this question to the electrically inclined - we live close so I took our 17 up to ETI and Reace installed the outlet & a couple other things.
I just ordered our 21 with outlets where I needed them.

[FMLNM]

Originally Posted by paulw

Its a Phillips brand I got at CPAP.com (I've been very happy with their prices & service).
CPAP.com - Shielded DC Cord for PR System One 60 Series Machines
I see there is also a generic one listed for a number of brands.
You may have to send them a copy of your prescription if you want to buy machines or masks from them, but the cord should be a simple transaction.

Thanks. I too have the System 1 60 series machine and that's exactly the cord that I thought I would need for my machine. My husband's machine is a Resmed S9 and requires a more expensive DC cord...but it only pulls 3.7Amps. The System One wants 6.7 amps. Sounds like it could all work out with the correct cords and cabling.