Solar panels and CPAP machines? - Page 3 - Escape Trailer Owners Community

Go Back   Escape Trailer Owners Community > Escape Tech > Escape Systems | Water, Waste, Charging & Propane
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 05-03-2014, 01:56 PM   #21
Site Team
 
cpaharley2008's Avatar
 
Join Date: Jun 2010
Location: York, Pennsylvania
Trailer: 2016 2ndGen Escape 19' PRAIRIE SCHOONER pulled by 2014 Ram Hemi/8sp
Posts: 13,658
Do these machines cycle on/off? Pulling 10 amps per hour is a lot over a 8 hour night!!
__________________

__________________
Jim
The two most important days in your life are the day you were born and the day you find out why………..Mark Twain
cpaharley2008 is offline   Reply With Quote
Old 05-03-2014, 02:16 PM   #22
Senior Member
 
FMLNM's Avatar
 
Join Date: Mar 2013
Location: Sandia Park, New Mexico
Trailer: 2008 Escape 5.0
Posts: 697
Quote:
Originally Posted by cpaharley2008 View Post
Do these machines cycle on/off? Pulling 10 amps per hour is a lot over a 8 hour night!!
The amount of air they are pushing varies with the breathing and the need, but they do run the whole time. The actually use time is more like 6 or 7 hours night...sometimes less. I wish I had the newer (by 3 months) machine my husband has since his only draws 3.7 amps.
__________________

__________________
Fran & Dave
2008 Escape 5.0
2011 Frontier Crew Cab Short Bed Pro4x
Sandia Park, New Mexico
FMLNM is offline   Reply With Quote
Old 05-03-2014, 03:16 PM   #23
Senior Member
 
alanmalk's Avatar
 
Join Date: Apr 2014
Location: Arvada, Colorado
Trailer: '21 - 'Velocity'. Tow: Toyota Tacoma V6, 4X4, manual.
Posts: 545
Quote:
Originally Posted by FMLNM View Post
The amount of air they are pushing varies with the breathing and the need, but they do run the whole time. The actually use time is more like 6 or 7 hours night...sometimes less. I wish I had the newer (by 3 months) machine my husband has since his only draws 3.7 amps.
I found some useful numbers on a CPAP Community forum.

1) For a "PR" machine: "Kill-A-Watt usage: Time: 9:10 and 0.06 KWH with 8:30 therapy hours." with no humidity.

2) For a "S9" machine with humidifier on, and no EPR: "shows a power consumption of 0.18 kwh for 6.7 therapy hours each night."

So, 60 watt hours or 180 watt hours totals depending on brand and/or humidity.
Assuming a pair of 6V deep cycle batteries can supply 1000 watts to the 1/2 discharge state, then 5 nights seems to be a reasonable number. That is assuming no recharge from solar and no other drains. AND it is assuming that the battery numbers are correct AND the CPAP posters are accurate. Lots of assumptions but I would be optimistic and say it is reasonable.
alanmalk is offline   Reply With Quote
Old 05-03-2014, 03:23 PM   #24
Senior Member
 
FMLNM's Avatar
 
Join Date: Mar 2013
Location: Sandia Park, New Mexico
Trailer: 2008 Escape 5.0
Posts: 697
Quote:
Originally Posted by alanmalk View Post
I found some useful numbers on a CPAP Community forum.

1) For a "PR" machine: "Kill-A-Watt usage: Time: 9:10 and 0.06 KWH with 8:30 therapy hours." with no humidity.

2) For a "S9" machine with humidifier on, and no EPR: "shows a power consumption of 0.18 kwh for 6.7 therapy hours each night."

So, 60 watt hours or 180 watt hours totals depending on brand and/or humidity.
Assuming a pair of 6V deep cycle batteries can supply 1000 watts to the 1/2 discharge state, then 5 nights seems to be a reasonable number. That is assuming no recharge from solar and no other drains. AND it is assuming that the battery numbers are correct AND the CPAP posters are accurate. Lots of assumptions but I would be optimistic and say it is reasonable.
Thanks Alan! I am encouraged given that we would NOT be using the humidifiers and would be getting good charging (hopefully full) during the day! BTW, what was the 9:10 time about in the first example?
__________________
Fran & Dave
2008 Escape 5.0
2011 Frontier Crew Cab Short Bed Pro4x
Sandia Park, New Mexico
FMLNM is offline   Reply With Quote
Old 05-03-2014, 03:36 PM   #25
Senior Member
 
alanmalk's Avatar
 
Join Date: Apr 2014
Location: Arvada, Colorado
Trailer: '21 - 'Velocity'. Tow: Toyota Tacoma V6, 4X4, manual.
Posts: 545
Just a wild guess since I am not familiar with the "Kill-A-Watt" meter. I'm thinking the 9:10 was the total time the meter was turned on - nothing to do with the time the CPAP was running. But in any case, given all the other assumptions, the difference between 9:10 and 8:30 is probably insignificant. In other words, probably the equivalent of running the water pump for 5 minutes more or less.
alanmalk is offline   Reply With Quote
Old 05-03-2014, 06:34 PM   #26
Senior Member
 
fudge_brownie's Avatar
 
Join Date: Nov 2008
Location: Janesville, WI, Wisconsin
Trailer: Escape 19 (sold) Escape 21 2014
Posts: 1,226
I would leave the humidifiers attached when using 12 volt, the air will still blow across the water and it will add some moisture. Just the heater for the water will not work. My understanding is the machines will sense you are on 12 volt and turn of the heater. Not quite sure how all that is possible as the 120 volt power cord have a brick to convert to a lower voltage and connect to the same jack on the back of the machine.

My experience has been with the Respronics.
__________________
Paul and Janet Braun
2003 Toyota 4Runner V8 now 2012 Toyota Sequoia V8
Escape 19' 2010 now 2014 Escape 21'
fudge_brownie is offline   Reply With Quote
Old 05-03-2014, 07:25 PM   #27
Site Team
 
cpaharley2008's Avatar
 
Join Date: Jun 2010
Location: York, Pennsylvania
Trailer: 2016 2ndGen Escape 19' PRAIRIE SCHOONER pulled by 2014 Ram Hemi/8sp
Posts: 13,658
Quote:
Originally Posted by alanmalk View Post
I found some useful numbers on a CPAP Community forum.

1) For a "PR" machine: "Kill-A-Watt usage: Time: 9:10 and 0.06 KWH with 8:30 therapy hours." with no humidity.

2) For a "S9" machine with humidifier on, and no EPR: "shows a power consumption of 0.18 kwh for 6.7 therapy hours each night."

So, 60 watt hours or 180 watt hours totals depending on brand and/or humidity.
Assuming a pair of 6V deep cycle batteries can supply 1000 watts to the 1/2 discharge state, then 5 nights seems to be a reasonable number. That is assuming no recharge from solar and no other drains. AND it is assuming that the battery numbers are correct AND the CPAP posters are accurate. Lots of assumptions but I would be optimistic and say it is reasonable.
I think your math maybe incorrect. A group of 6v batteries will provide around 250 hours, at 40% would be 100 available hours. Using a combined 10 hours per hour for 6-8 hours means one night use before needing charging.
__________________
Jim
The two most important days in your life are the day you were born and the day you find out why………..Mark Twain
cpaharley2008 is offline   Reply With Quote
Old 05-03-2014, 09:49 PM   #28
Senior Member
 
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 9,040
Quote:
Originally Posted by alanmalk View Post
Assuming a pair of 6V deep cycle batteries can supply 1000 watts to the 1/2 discharge state...
My guess is that this was intended to mean 1,000 watt-hours, or about 80 amp-hours at 12 volts... perhaps reasonable for a pair of Escape-sized batteries.

Quote:
Originally Posted by cpaharley2008 View Post
A group of 6v batteries will provide around 250 hours, at 40% would be 100 available hours.
If you assume 250 amp-hours of capacity, 40% of that would be 100 amp-hours... or 50% would be 125 amp-hours. 125 amp-hours at 12 volts would be 1500 watt-hours.

I believe that Alan is assuming a significantly lower total battery capacity than Jim (2,000 W-h or 160 A-h from Alan, versus 250 A-h or 3,000 W-h from Jim).

Quote:
Originally Posted by cpaharley2008 View Post
Using a combined 10 hours per hour for 6-8 hours means one night use before needing charging.
"hours per hour" makes no sense, so I assume this was supposed to be "10 amp-hours per hour" (average 10 amps or 120 watts, for two units), but the values Alan quoted earlier indicate only 60 watt-hours for 8.5 hours of use of single unit, or an astoundingly low 8 watts average consumption. It looks like there's a large difference in the power consumption assumptions here.

It doesn't help when people leave out half of the units of measure...
Brian B-P is offline   Reply With Quote
Old 05-04-2014, 02:32 AM   #29
Member
 
Join Date: Nov 2012
Location: Forks, Washington
Trailer: Working on my build list
Posts: 93
The dental device escape artist mentions can be a good option, they work for a lot of people. If it worked for just of one of you it would help. If it didn't help, I'd hate to run just one machine. If both of you have sleep apnea, that's not healthy for the person without a machine.

Consider trying it with your normal camping usage. How much you usually use the lights, furnace etc. also effects how low your batteries are in the morning. A night spent with the CPAP machines running plus your other use will tell you what you need. It's really hard to predict how much power you use overnight. If there is a way to spend one night in the trailer before you leave for a longer trip you will learn.

Since your health is at stake, a good battery monitor would be worth considering. It will let you keep close watch on the batteries and make sure you charge enough and don't overdraw them. Batteries are only designed to be drawn down a certain percent. If you go deeper than that you will ruin them. They also don't like never getting to full charge. The difference between batteries that last 1-2 years and batteries that last 5-6 years is how well they are cared for. They are too expensive to replace to abuse them.

Another option is to increase the amount of solar and/or battery power available. If you have enough battery capacity but it charges too slowly another solar panel might be the answer. If it is both charging and storage that is lacking you might need another one or two more panels plus two more batteries.

A portable solar panel would be the fastest way to add charging capacity. Or you might prefer a second panel on the roof. There are pros and cons with either approach. You will find lots of discussion if you search.

Adding batteries is more of a problem since there are concerns with weight, space and ventilation. I'm not familiar enough with the 5.0 to guess where you would have to put them. In a few years, when lithium batteries are ready for mass commercial use they will be the best way to go. Right now, if you are not an early adopter of high tech gear, you won't want them.

This thread shows a 19 with two solar panels and four batteries: 2nd Solar Panel I know it is not a 5.0 but it will give you some idea what is possible with a little creativity.

It will also depend on what season and part of the country you are in. Since you are in the southwest I agree that you will have optimal conditions much of the time. However, in your place, I would want to have enough reserves to ride out a cloudy day or two.
WestEnder is offline   Reply With Quote
Old 05-04-2014, 12:10 PM   #30
Senior Member
 
FMLNM's Avatar
 
Join Date: Mar 2013
Location: Sandia Park, New Mexico
Trailer: 2008 Escape 5.0
Posts: 697
Thanks Westender...good suggestions. We are fortunate that neither one of us has really severe sleep apnea - I wasn't even aware I had it until I had a study done - so I think we (especially me) would not be harmed by a few nights without it. Also we live at about 7000 feet and if we are camping at a lower elevation, which is often the case, we automatically get a bump up in oxygen for a few days!
We are in the process of ordered in the appropriate power cords to run off 12v. Each machine is different and specific in its requirements
We do have plans to do a 'dry run' overnight at home and see how the battery responds. That will give us valuable information for sure. We had already converted our lights to leds so that helps.
Thanks again,
Fran & Dave
__________________

__________________
Fran & Dave
2008 Escape 5.0
2011 Frontier Crew Cab Short Bed Pro4x
Sandia Park, New Mexico
FMLNM is offline   Reply With Quote
Reply

Thread Tools
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






» Virginia Campgrounds

Reviews provided by



All times are GMT -5. The time now is 02:51 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 Social Knowledge, LLC All Rights Reserved.