Boondocking with CPAPs
- Thread starter dandelion
- Start date
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If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
Mark_K5LXP
Well-known member
Lots of moving parts to that problem. You need to more concisely define your operating requirement.
Mark B.
Albuquerque, NM
- What is the power draw of these units, how many hours per day, and for how many days?
- Any existing power resources - battery, solar, generator? How much is restored and how often?
- Any power conversion required, i.e. are these 120V units or can they be operated off DC?
Mark B.
Albuquerque, NM
Roy M
Well-known member
I used a 400W inverter which worked fine until the house battery didn't charge due to a wiring problem.
Isaac-1
Well-known member
As Mark says there are a lot of moving parts to this answer, not the least of which is how much power does YOUR CPAP consume, as some draw a lot more power than others. Add to this where and when do you camp, Solar works great for open spaces with lots of sunshine, not so much if you camp under the trees in a cloudy climate, ...
AStravelers
Well-known member
Many or most CPAPs, if you will turn off the humidifier or heated hose, will only draw about 1 amp or less. So that is about 8AH a night. If you have to have the humidifier or heater on you are looking at 5-7 amps or 40 to 60AH a night.
If you have a 2000 watt inverter and you have to have it on all night to just power the CPAP it will pull 1-2 amps just operating the inverter, not counting the power the CPAP uses. So add that to your power requirements.
Many or most CPAPs operate with 12V or 24V DC. The power cords they come with convert the 120V to the DC voltage needed by the CPAP. Look at the power label, usually on the bottom of the CPAP, to see what voltage it uses.
If your CPAP runs off of 12V you can usually buy a power cord to plug into 12V. If it a 24V device you can buy a 12V to 24V converter to run it.
One more option is to buy a small 100-200watt inverter to power the CPAP. Those small inverters will still use some power to just operate the inverter, but hopefully it will be less than the big inverter.
If you have a 2000 watt inverter and you have to have it on all night to just power the CPAP it will pull 1-2 amps just operating the inverter, not counting the power the CPAP uses. So add that to your power requirements.
Many or most CPAPs operate with 12V or 24V DC. The power cords they come with convert the 120V to the DC voltage needed by the CPAP. Look at the power label, usually on the bottom of the CPAP, to see what voltage it uses.
If your CPAP runs off of 12V you can usually buy a power cord to plug into 12V. If it a 24V device you can buy a 12V to 24V converter to run it.
One more option is to buy a small 100-200watt inverter to power the CPAP. Those small inverters will still use some power to just operate the inverter, but hopefully it will be less than the big inverter.
AStravelers
Well-known member
Also, if you are going to do more than an occasional night or two dry camping or boondocking then you really need to have a shunt based battery monitor like the Victron 712, Victron smart monitor or a Trimetric. The Victron's have blue tooth to connect to your phone.
These monitor, show you the total amount of AH's discharged from your batteries and the number of AH's put back in. They also show the state of charger (SOC) of your batteries. You really need to get your batteries back to 100% full every 5-7 days or the sulfate and you rather quickly reduce the capacity of your batteries.
These monitor, show you the total amount of AH's discharged from your batteries and the number of AH's put back in. They also show the state of charger (SOC) of your batteries. You really need to get your batteries back to 100% full every 5-7 days or the sulfate and you rather quickly reduce the capacity of your batteries.
Isaac-1
Well-known member
I want to partly disagree with this last post, while that was true of older inverters, newer pure sine wave inverters are much more efficient at low draw loads, though they still perform best at near full load. A modern 2000 watt inverter may only draw half an amp or less at light loads. My Xantrex Prowatt SW 2000 inverter which is about a 10 year old design draws under .8 amps at no load. So still a noticeable amount it is not nearly as bad as most older modified sine wave inverters.
Also while modern shunt based power montiors are nice, they just tell you exactly how much power you have left, they do nothing to increase the amount of power. Personally if it were me and I had the choice between spending money on more power generating / storage capacity,(solar panels, or batteries) vs monitoring, I would opt for more capacity.
Also while modern shunt based power montiors are nice, they just tell you exactly how much power you have left, they do nothing to increase the amount of power. Personally if it were me and I had the choice between spending money on more power generating / storage capacity,(solar panels, or batteries) vs monitoring, I would opt for more capacity.
AStravelers
Well-known member
I guess my 7 year old Magnum 2012, 2000 watt inverter/charger is an antique. It pulls about 1.5 amps just being turned on.
About the battery monitors. If you don't know that you are discharging below 50% full and then not getting above 70% to 80% full on a daily basis, you will quickly reduce the capacity of your batteries.
It is kind of like driving w/o a fuel gauge combined with not being able to know if you have filled up your fuel tank or how many gallons you have put back in. Or not knowing how full/empty your black or gray tanks are or your fresh water tank is.
On the other hand if you are consistently back on shore power after 1-4 nights of dry camping then you really don't need the monitor. You can get by with just getting your batteries back to 70% full or discharging to 40% full for a few days.
About the battery monitors. If you don't know that you are discharging below 50% full and then not getting above 70% to 80% full on a daily basis, you will quickly reduce the capacity of your batteries.
It is kind of like driving w/o a fuel gauge combined with not being able to know if you have filled up your fuel tank or how many gallons you have put back in. Or not knowing how full/empty your black or gray tanks are or your fresh water tank is.
On the other hand if you are consistently back on shore power after 1-4 nights of dry camping then you really don't need the monitor. You can get by with just getting your batteries back to 70% full or discharging to 40% full for a few days.
Isaac-1
Well-known member
I would say it is more like driving with an old fashioned gas gauge where you only know 1/4, 1/2, 3/4 and Full, and even then it is a ballpark basing upon using a volt meter and lead acid batteries, where a shunt style power meter is more like the fuel economy and miles to empty display on a modern car. Of course the voltage gauge method does not work on Lithium Ion batteries as they have such a flat discharge curve.
p.s. Al, i don't know if you have an ME2012 or an MS2012, but based on first available date on Amazon it looks like these models were introduced in 2009 and 2010, maybe earlier
p.s. Al, i don't know if you have an ME2012 or an MS2012, but based on first available date on Amazon it looks like these models were introduced in 2009 and 2010, maybe earlier
House Husband
Well-known member
I use a 12 volt Philips Dream Station w/out humidifier. No inverter needed. 12 volt cigarette cord available in E Bay & Amazon.
Richard
Richard
Boondocking means 12 volt power supply.
This is not hard -- if your C-pap manufacturer can supply you with 12 volt adaptors for your machine.
My wife and I each use c-paps and we boondock. I use the humidifier and heated hose in winter. My wife doesn't use either.
First, check with your C-pap maker to see if they have a 12 volt power supply adaptor. I strongly recommend you get the 12 volt adaptors directly from the C-Pap manufacturer to make sure you get high quality and don't void any warranties. I ordered a 12 volt power supply for each machine directly from Resmed, who makes our C-paps. In the trailer I installed a 12 volt outlet (cigarette lighter style) on each side of the bed. I connected each to a 12 volt circuit that Grand Design had already (thoughtfully ;-) installed on one side of the bed for charging computers, phones and the like. My circuit goes back to the power converter and is 12 gauge wire. If you need to run your own wire, use 12 gauge which is sufficient for 2 machines. 12 volt DC needs heavy wire to avoid line voltage loss. You should be able to run it either directly to the battery or to the converter. MAKE SURE YOUR BATTERY IS REALLY A DEEP CYCLE. This is key. Otherwise the battery will not last long at all. Our two machines can run for at least 8 hours each night. Each morning I run the generator until the RV battery is recharged. No more than 2 hours.
My cost was about $100 for 8 feet of 12 gauge to go from one side of the bed to the other, marine style wiring connectors (the best kind), two 12 volt outlets, and two 12 volt adaptors from RESMED. It took me an afternoon to run the wire, make connections, test the voltage, and install the 12 volt power outlets. The 12 volt adaptors from RESMED were the most expensive, about $40.00 each. Plus the Generator of course.
Running the C-Paps off the power converter allows you to use the 12 volt adaptors if you are hooked up to regular power without pulling from the battery, and relying on the converter to sense that the battery is discharged and needs charging. It's worked for us for a year.
This is not hard -- if your C-pap manufacturer can supply you with 12 volt adaptors for your machine.
My wife and I each use c-paps and we boondock. I use the humidifier and heated hose in winter. My wife doesn't use either.
First, check with your C-pap maker to see if they have a 12 volt power supply adaptor. I strongly recommend you get the 12 volt adaptors directly from the C-Pap manufacturer to make sure you get high quality and don't void any warranties. I ordered a 12 volt power supply for each machine directly from Resmed, who makes our C-paps. In the trailer I installed a 12 volt outlet (cigarette lighter style) on each side of the bed. I connected each to a 12 volt circuit that Grand Design had already (thoughtfully ;-) installed on one side of the bed for charging computers, phones and the like. My circuit goes back to the power converter and is 12 gauge wire. If you need to run your own wire, use 12 gauge which is sufficient for 2 machines. 12 volt DC needs heavy wire to avoid line voltage loss. You should be able to run it either directly to the battery or to the converter. MAKE SURE YOUR BATTERY IS REALLY A DEEP CYCLE. This is key. Otherwise the battery will not last long at all. Our two machines can run for at least 8 hours each night. Each morning I run the generator until the RV battery is recharged. No more than 2 hours.
My cost was about $100 for 8 feet of 12 gauge to go from one side of the bed to the other, marine style wiring connectors (the best kind), two 12 volt outlets, and two 12 volt adaptors from RESMED. It took me an afternoon to run the wire, make connections, test the voltage, and install the 12 volt power outlets. The 12 volt adaptors from RESMED were the most expensive, about $40.00 each. Plus the Generator of course.
Running the C-Paps off the power converter allows you to use the 12 volt adaptors if you are hooked up to regular power without pulling from the battery, and relying on the converter to sense that the battery is discharged and needs charging. It's worked for us for a year.
My experience....IF you have a deep cycle house battery, a generator, and a modern DC power converter, than the RV battery monitor that came with the unit is sufficient, as long as you run the generator each morning for a couple of hours. The added expense of a high tech, battery monitor et all is not needed to add a couple of 12 volt adaptor powered C-paps.
C-Paps that can be powered by 12 or 24 volts to 12 volt adaptors avoids using DC to AC inverters and the inherent inefficiency of such devices.
The best way to power a 12 volt cpap is solar, backed up by a small generator.
Domo
Well-known member
My resprionics CPAP is powered by an external power supply that plugs into the wall. That power supply puts out 12 VDC and the polarity of it's plug is printed on the label of the transformer - so it was pretty simple to figure out how to eliminate that big chunk of electronics.
So - I ordered a cigarette lighter style cord for 12 VDC. Installed a cigarette lighter socket near the bed and plug the CPAP in that way - no inverter needed, no big bulky transformer - just a cord. Easy to do.
You can make your own pretty easy... or just buy one at NAPA... just make sure the plug fits in the CPAP. I did mine for about $40 for all the parts, sockets, wire, fuse...
So - I ordered a cigarette lighter style cord for 12 VDC. Installed a cigarette lighter socket near the bed and plug the CPAP in that way - no inverter needed, no big bulky transformer - just a cord. Easy to do.
You can make your own pretty easy... or just buy one at NAPA... just make sure the plug fits in the CPAP. I did mine for about $40 for all the parts, sockets, wire, fuse...
Hooking up a 12 or 24 volt CPAP (or two) is a LOT easier than you think. The hardest part is getting 12 volts to the bedside from the power converter or battery. And the only thing to worry about is making sure that your RV battery is a true deep cycle and /or that you can recharge it every day, or every couple of days. If you have an inexpensive portable generator and a deep cycle battery you don't need fancy battery monitors, inverters, or other electronic equipment.
meaningful_meanderings
Member
Another solution is talk to your physician about an oral appliance (mouth piece). The CPAP did not work well for me so was fitted with the mouthpiece (no idea why it was the last option, not even mentioned until the CPAP was proven to be less that useless.) It pulls the lower jaw forward so the airway cannot obstruct.
