Please design me a system

[Darton]

Hey guys I have sleep apnea which I use a CPCP machine when I sleep. It's basicly a air mask that forces air into my airway to keep it open while I sleep. I've used this machine since 2001. I haven't been able to ever take it out camping due to the lack of reliable electricity. I've been thinking recently about a solar regharging 12v power system to power my machine so I can take it camping and get a good nights sleep while i'm out there.

I was surprised to see on the manufacture's website that there is quite abit of info on the power requirements needed to run the machine on 12v. So what I need is a reliable, inexpensive, and relativly small setup that will allow me to travel with the machine.

I'd like a 12v deep cycle battery, solar panel for recharging during the day time, and an inverter.What all will i need and where can I find it?

The power requirements for the machine are:
-A modified sine wave inverter of 150 watts or more.
-The current draw at 12v dc is 1.28 amps
-Battery size for 8 hour use including a 50% saftey margin is 16 amp-hours

I'm not sure what all of this means as I'm not very electrically inclined. please let me know what I will need to power and recharge a system. I'd like to stay as low budget a possiable but be able to use the machine on battery power over night for 6-8 hours and then recharge it by solar during the day. Any help is appreciated.

 

[UK4X4]

Darton,

I'd be happy to help- is that current all the time of does it just kick in when required.

ie monitors breathing the whole night and kicks in when required or does it provide forced air the whole time ?

Being that its life saving equipment I would not advise a single power source system.

You could build a primary solar system, but when power drops to low levels it switchs to its backup power, for example your truck battery, and alarms when it does so, but there may be simpler ways of doing it and just have solar as a daily top up

Give us some more information on how the system works and what you need to accomplish ?

 

[Darton]

Hey thanks. It runs constantly the whole time it's on. My condition is not nearly as sever as most people so I can sleep without the machine but I sacrafice a good nights sleep as I never really fall into deep sleep and am constantly waking up not to mention the snoring that those around me say I do. If I don't use the machine I usually fell really tired and groggy the next day due to the lack of sleep. My primary overnight vehicle is an 05 jeep wrangler so I'm not so sure a backup system attached to the jeep battery would work since I rarely sleep close enough to it that i wouldn't need a looong power wire. It would be nice to have a way to "plug in" the system to the jeep to charge it if I needed to.

 

[TreeTopFlyer]

Are there any special devices running on it besides a pump? I ask because of the use of a modified sine inverter. If it has any monitoring equipment, those might not play nice with the chopped wave "modified sine". 99% of the time, it doesn't matter. If it's just a plain 'ol pump, a nice xantrex or statpower inverter, a deep cycle like the optima 55Ah or something comparable will work. Depending on the size of your machine, you could try and find a storage box and fit everything in it as a unit.

If you don't want that large of a battery and you ONLY use it for the machine, you could use one of the 12V sealed batteries like the ones used as APC backup or for wheelchairs

That would give plenty of capacity and give a buffer of reserve in case the solar charger didn't recoup all the lost charge. You'll need about 35 watts to recover the drain from the night before. Kind of pricey if you are going solar. A 13watt kit from Northern Tool is $120. At best you'd get maybe 4-6Ah of charge back per day.

Like UK4X4 said, have two sources for power. Solar to top off and vehicle to charge up while driving. Just depends on how you want this system to work, stand alone, somewhat integrated to the vehicle, several options to attack from. Start nailing down the needs and a more detailed plan of attack can be made.

 

[buddha]

Google "cpap battery camping" and you will find a plethora of info. The website for the company of my machine also has info on what to do. Yours may as well, so it's worth checking out. Battery backup systems are fairly common.

I have the same condition, and have not been camping with my cpap yet, but intend to this year. From my research, a simple car battery will power a cpap for three nights before needing a recharge. I'm planning on testing mine off my truck battery before heading out into the boonies. I bought a simple power inverter from Wally World that meets the specs. Power inverters will list the specs on the side of the box so you can compare to what you've given. I've found that many people have done this, so I'm fairly confident it will all work ok. Nonetheless, test locally before going remote.

Ultimately, I'll rig up a dual battery system in my truck to power my cpap, but I also do a lot of motorcycle camping, which prohibits such a system, so I'll be depending on my bike battery. I'm told as long as you ride a good distance every day, your battery should recharge well enough to power your machine each night...

After sleeping with a CPAP for about as long as you, I really can't sleep without it anymore. I never became fully awake during the night before using a CPAP, but now, if I fall asleep without it, within a couple of hours I'll wake up gasping for air, my heart pounding.

Good luck, and let us know what you end up doing.

 

[Tennmogger]

Hi,

Could you refer us to that manufacturer page? Does it have a wall transformer/power supply, a power supply in the line going to the machine, or does the AC cord run into the machine itself. What I'm getting at is if there's a way to run it directly off 12v dc or not. Your post sort of indicated it'd run off 12 vdc.

-The current draw at 12v dc is 1.28 amps

If that's the case, I'd recommend any good 12vdc deep discharge battery. Your specification of 16 AH or more could be considered a minimum. If it were me, I'd look at a battery that could be used for other things, too, like an Optima deep discharge battery that could even go into the vehicle in case of it's battery failure. To charge, just plug it into the Jeep cig lighter while you are driving. A solar panel large enough to recharge the battery in one day (by the amount of ampere hours used at night) would be expensive and bulky, and you'd need a charge controller. I'd put that money into the battery. The machine would run for days off an Optima.

I picked up a 400W modified sine wave inverter at West Marine for $40 that works well. Most likely your machine would run just fine on modified sinewave. Go by the manufacturer specs.

Bob

 

[Tucson T4R]

I sometimes use my CPAP machine when out camping. Since they can run directly off 12V DC, there should be no need for the inverter. An inverter would be used if you want to plug it into 110VAC.

I run mine directly off the 12V system in my trailer but you could just as easily plug it into your truck 12V plug. I recommend setting up a dual battery system in your truck. That way you get the capacity you need to run the CPAP and the added benefits of the dual batteries in your truck.

 

[Darton]

Are there any special devices running on it besides a pump? I ask because of the use of a modified sine inverter. If it has any monitoring equipment, those might not play nice with the chopped wave "modified sine". 99% of the time, it doesn't matter.

Yeah it's just a pump from what I can tell. The company website said to onle use a modified sine wave inverter.

 

[Darton]

From my research, a simple car battery will power a cpap for three nights before needing a recharge.

I didn't realize this. I'm usually not out for more than 3 or 4 nights at a time.

 

[Darton]

Could you refer us to that manufacturer page? Does it have a wall transformer/power supply, a power supply in the line going to the machine, or does the AC cord run into the machine itself. What I'm getting at is if there's a way to run it directly off 12v dc or not. Your post sort of indicated it'd run off 12 vdc.

some of the newer machines have 12v direct plug in adapters. mine doesn't. So i'd have to plug the cord into an inverter for power. I can't find the mfgr page again. I dloaded a pdf from them months ago and was quoting info from it.

 

[TreeTopFlyer]

Go to harbor freight and get the cheapo meter here

Then pick up a low power inverter 150watts or so. You pump is only pushing about 20 watts. But since it's a motor it will have take a little more than that to start but once it's going, it's only pulling about 20W.

Buy one of those 12V sockets like this

Run the wires from the socket to your truck battery, plug in the inverter to the 12v receptacle, plug in your CPAP and turn it on. Then clamp the meter around the + wire to get the current draw. Now you know how much it's taking to run both the CPAP and inverter. To me, it's worth knowing

If you want cheap, buy all that and run it off your truck battery while camping. Just make sure you aren't running much else, you don't want to have a battery too weak to start when you wake up in the morning.

Little more pricey: buy a 2nd battery, install a perko switch (or no switch and just parallel for even cheaper)and run the CPAP from that, just remember all the do's and don't when running the switch.

More Pricey: Get an automated battery controller, Luna, Hellroaring, Xantrex take your pick.

Most Expensive: Automated controller, 2nd battery, solar controller and panels, etc.

With as little draw as that motor has you could run it off the vehicle battery, but just be cautious of what you run while camping, i.e. radio, lights, etc.

 

[Tucson T4R]

some of the newer machines have 12v direct plug in adapters. mine doesn't. So i'd have to plug the cord into an inverter for power. I can't find the mfgr page again. I dloaded a pdf from them months ago and was quoting info from it.

My CPAP machine was purchased through my medical insurance. If yours was also purchased through your medical insurance, they may be willing to replace the unit with a current model that has a 12V input power option.

It's worth checking into if you still have the CPAP system covered by medical insurance.

 

[slomatt]

Darton,

Tucson T4R's suggestion about upgrading to a CPAP machine that can run on 12v is a really good one. Inverters don't have a great efficiency and you'll loose a good amount of the available power to heat. If you can run off of 12v a nice option would be to get a portable battery jumper and take that into your tent with you. Most of these jumpers put out 10-16AH and have a cigarette lighter plug you could plug the machine into. During the day you could charge the jumper off of your truck's battery or off of solar.

Some companies (such as Resmed) require you to use their 12v adapters or else the warranty will be voided. For some reason they don't use the standard polarity on the plug and I've heard of people frying their device, which is an expensive problem.

What happens to your airflow if the power to the CPAP machine is cut? I would assume you can still breath (though it would be restricted by the mask) but since you have an older machine it would be good to know what would happen in the worse case scenario.

- Matt

 

[Darton]

Darton,

Tucson T4R's suggestion about upgrading to a CPAP machine that can run on 12v is a really good one. Inverters don't have a great efficiency and you'll loose a good amount of the available power to heat. If you can run off of 12v a nice option would be to get a portable battery jumper and take that into your tent with you. Most of these jumpers put out 10-16AH and have a cigarette lighter plug you could plug the machine into. During the day you could charge the jumper off of your truck's battery or off of solar.

Some companies (such as Resmed) require you to use their 12v adapters or else the warranty will be voided. For some reason they don't use the standard polarity on the plug and I've heard of people frying their device, which is an expensive problem.

What happens to your airflow if the power to the CPAP machine is cut? I would assume you can still breath (though it would be restricted by the mask) but since you have an older machine it would be good to know what would happen in the worse case scenario.

- Matt

Yeah at my next check up i'm gonna see about upgrading to a new machine. I haven't seen the doc in awhile. My cpcp is a resmed but they don't make and inverter or adapter for it. I found some portable power packs for cpap machines today online hut they are expensive. I can't justify spending $350 for one when I think I can assemble my own operation for 1/3 the cost.

 

[Darton]

I also have a CPAP machine at home that is set to 14 psi. I tried the inverter also and decided it was better to have the dental appliance when I am out. My insurance also paid for that appliance. They say it is not as effective as the CPAP but it works for me.

I totally forgot about the dental appliance. I've seen them online for around $60. I have a CPAP pressure of 7 so maybe the mouth piece would work for me. HMMM... have you seen the ones online? How similar are they to yours?