My answer to camping / backup problem

[bige94]

Ok, here is a quick write up of my answer to camping and backup.

So I have begun to camp with scouts and leaving my cpap at home is not a choice. I have to take it. I spotted the LiIon Batt packages and thought I can do better. The LiIon batts are expensive even if ordered from the Chinese manufacturer (I checked). I decided to go with deep cycle sealed lead acid batts instead.

I purchased two sealed LA batts from amazon. Each is 12v and 12ah. The LiIon batts were only 7.5ah. I also procured another cpap like i have at home and removed the humidifier. Both batts and the Cpap fit nicely into a marine batt box I purchased at walmart.

I added a 12v multiplier device that fits in the cup holder of your car. This added the capability of two 5v usb ports as well as 2 12v cig plugs.

After cutting the hole in the marine box and fabricating some brackets to support the extender I fit it all together. Nice.

I then modified the wiring on the 12v multiplier to separate one cig plug all by itself. This will be the cpap side. The other side includes the 12v cig plug and the 2 5v usb ports. The idea here is that you have a dedicated batt to run just the cpap. After all the cpap is the whole reason for the project. The other batt will run a second plug for something and the I can use the usb to charge my phone. I could have run the batts in parallel and had twice the capacity, but I didnt want to risk draining the batt on something else.

I figure I can get 20hrs (4 or 5 days sleep for me) out of one batt using the cpap. That is a guess using a calculator that tried to determine how long a LiIon batt would last at my pressure. Im sure you have seen it if you have looked at the batt backups. The batt they sell has fewer AH.

The whole thing runs in the box with the lid shut. The hose fits out the box vent perfectly. I am going to add switches for each batt so I can guarantee that the power is off. That will allow me to kill the cpap without opening the box too.

Sorry for the quick and dirty write up, I am in a hurry. Just wanted to throw it out there for your consideration.

Click here for pictures

Comments welcome.

[PaulaO2]

I would test that system several nights before you trusted it.

The U1 batteries do not hold their charge for very long. Do a few test nights and let us know how it works out!

However, I love the set up. It looks easy to transport and keeps everything together.

[bige94]

I would test that system several nights before you trusted it.

The U1 batteries do not hold their charge for very long. Do a few test nights and let us know how it works out!

However, I love the set up. It looks easy to transport and keeps everything together.

My thoughts as well. I have used it one night with no issues. I only sleep for 4 or so hours so I can get more nights than the average joe.

I'll do some testing and post the results.

[A C Hunter]

Do you run your setup with the cpap inside the battery box?
Where does it draw air?
No problem with hydrogen gas from the lead-acid batteries?

I'd also be concerned about acid (sulphur) corrosion on your electronics over the long term....

Keep us posted - I would like to resume camping too!

AC

[PaulaO2]

The U1, like most deep cell batteries, are sealed so there should be very little vapor and no leaks.

But you do have a point.

You may want to cut a section on the side out and put in some sort of grid to let air in. Even though there's little vapor leaking, you don't want it to build up. I guess you could use it with the lid up.

[Sleepster]

That's a nice set up. You might want to add a solar charger. Also, since you're obviously handy with these things, you could rig up a plug that allows you to charge the batteries by plugging them into the cig lighter socket on your car.

[bige94]

The U1, like most deep cell batteries, are sealed so there should be very little vapor and no leaks.

But you do have a point.

You may want to cut a section on the side out and put in some sort of grid to let air in. Even though there's little vapor leaking, you don't want it to build up. I guess you could use it with the lid up.

Yes I do run it inside the box. It's all self contained. There are huge holes in the box already. The lid has spaces that overlap the sides of the box to allow wires to protrude from the box while it's shut. I would never assume that there was enough draw from the Cpap to pull air in through the cracks.

The batteries are sealed and if there shouldn't be any buildup to worry about.

I may add a charging port later on. I would have to run the batteries in parallel to charge them both at the same time. I could add switches to isolate each battery when I was ready to use it. That way I can still run the Cpap on one battery.

If nothing else it's a good start.

I'm surprised that no one mentioned the filter I'm using. I have been using furnace filters for years.

[PaulaO2]

That's the white thing sticking out? I though maybe you were using a Swiffer pad. I use them in my computer.

[bige94]

That's the white thing sticking out? I though maybe you were using a Swiffer pad. I use them in my computer.

That would be the furnace filter. I have been using them for years. I buy the high end furnace filters and then cut them to fit.

[Sleepster]

That would be the furnace filter. I have been using them for years. I buy the high end furnace filters and then cut them to fit.

One of the advantages of CPAP therapy is that we get our own personal supply of filtered air. If you have allergies to things like dust mites, this solves a lot of problems. There's no need to bother with those pillow and mattress covers, hypoallergenic blankets, and all that stuff.

If furnace filters work for you, that's great. I get my filters from my DME at esentially no cost. There's a foam pre-filter and fine mesh filter. I doubt a furnace filter would be as good at capturing the really tiny particles, as furnace filters are designed for a much faster air flow, but if they worked for me I'd use them, too.

That's a really nice system you've crafted for yourself. I guess when you sleep only four hours a night you've got lots of time on your hands for creative projects.