Added 12V Receptacles on each side of bed.

[Mach428]

My wife and I both use CPAP machines, which run on 12V. I wanted to add the receptacles so that we could leave the 120vac cord and brick in the house. Besides, now we can boondock without converting 12v to 120v to 12v.

I contacted the CPAP store without model number and they proved the 12v cords with a cigarette lighter end.

I added two fused circuits to the power distribution center under the bed. Works great!!

[5picker]

Never happened without pics...

[Mach428]

Sorry. I'll add pics of this and many other mods.

[newRVer]

Mach,

My wife just picked up her CPAP machine last week and I've already been thinking about how this would work in my 3011 RV. I saw the 12V outlets that you installed in the bed base on the other thread, was there a 12V source nearby that you tapped into? Also, where do you place the CPAP machine itself?

RVr

[Mach428]

The power distribution center is under the bed. I installed two additional circuits with 15 amp fuses from the 12 volt side. Mine had an additional 4 circuits that were unused so I still have two left. If you remove the front cover, you will see that the AC and DC sides are separated. Very easy to do.

We put our machines on the little built-in stands on either side of the bed.

[Mach428]

NewRVr, check the brand of machine and contact the manufacturer to ensure it's 12v (most of them are) and they can supply the 12v power cords. One end plus into your machine; the other has a cigarette lighter plug that goes directly into the receptacle.

[rocco52]

Originally Posted by Mach428

The power distribution center is under the bed. I installed two additional circuits with 15 amp fuses from the 12 volt side. Mine had an additional 4 circuits that were unused so I still have two left. If you remove the front cover, you will see that the AC and DC sides are separated. Very easy to do.

We put our machines on the little built-in stands on either side of the bed.

You are lucky all you needed were chords. I did the same thing although a different way but my CPAP's required adapters to drop the voltage down from 12 volts. $90 each.

[tomkatb]

My dealer arrange to have a 12 outlet in the bed area on my side.

Been using a cpap for 20 years. Had an outlet in the sailboat.

The bad thing is they are hungry devils. When parked I use the 110.

[Mach428]

Originally Posted by rocco52

You are lucky all you needed were chords. I did the same thing although a different way but my CPAP's required adapters to drop the voltage down from 12 volts. $90 each.

I don't understand. I've never seen a machine that operates on < 12 volts. Typically, the power cords with the inline brick drops the voltage from 120 to 12, thus the power cords that I got skips the 120 volt conversion and plugs directly into 12 volts.

[rocco52]

Originally Posted by Mach428

I don't understand. I've never seen a machine that operates on < 12 volts. Typically, the power cords with the inline brick drops the voltage from 120 to 12, thus the power cords that I got skips the 120 volt conversion and plugs directly into 12 volts.

Sorry it wasn't the voltage that our units need dropped it was the amps. The output of both the AC and DC converters for the Resmed Airsense 10 is 12 volts 3.7 amps. Other models or brands may have built in converters that handle this.

[newRVer]

Originally Posted by Mach428

NewRVr, check the brand of machine and contact the manufacturer to ensure it's 12v (most of them are) and they can supply the 12v power cords. One end plus into your machine; the other has a cigarette lighter plug that goes directly into the receptacle.

The one she is using now has (Phillips Dreamstation) has a 12V power cord option. However, on our 3011 the 12V power center is up front in the stairwell and not under the bed. I will have to take a look but I think the USB outlets under the bed convert from 12V to USB and she does not use the ones on her side. so that might be a 12V option I can use.

[Mach428]

None of them, that I'm aware of, have 12v power receptacle at the bed, which is why I added one on each side. I've read SO many posts about tapping into lighting wires etc.

Adding circuits to the power distribution center is very easy and straightforward

[Walholler]

My DW & I both use the CPAP machines, both of ours will operate on 12V. I too added two 12V outlets in our bedroom, one on each side of the bed. I tapped into the reading lights above the bed and put the outlet in the cabinets. Sorry, no pictures 5picker, use your imagination if one exist.

[Larry-NC]

Originally Posted by rocco52

Sorry it wasn't the voltage that our units need dropped it was the amps. The output of both the AC and DC converters for the Resmed Airsense 10 is 12 volts 3.7 amps. Other models or brands may have built in converters that handle this.

Rocco, sorry but you have been misled. The solution you have is acceptable but overly expensive.

Voltage defines the potential of the power. You must match the voltage of a source to the voltage required by a load. For example, if you connected a 24 volt incandescent lamp to your 12 volt trailer, it would glow a dull red instead of a hot white.

Current is how much electrical flow a particular load requires. For example, the 1141 lamp used in most pre-LED trailers draws 1.8 amps at 12 volts. The (brighter) 1156 lamp draws 2.1 amps at 12 volts. Fans may draw 3-5 amps. An electric awning might draw 8-10 amps.

The only relevance to amps in a trailer is that if you connect too many loads to a particular 12 volt circuit, a fuse will blow. For example, if you had a 15 amp fuse on a circuit with 10 1141 lamps, the amps add up to 18 amps and after several minutes the fuse will blow.

Most of the circuits in a trailer are fused for (and will safely supply) 15 amps. Such circuits would easily supply 2 x 3.7 amps along with some lighting.

[Bama Rambler]

The issue is that Resmed machines (and some others) use 24VDC instead of 12VDC, So you're still going to have to have some sort of power supply to change the 120VAC to 24VDC or use a boost converter to raise the 12VDC to 24VDC. And, they do draw almost 4 amps @ 24 volts, so that's 8 amps @ 12 volts.

[Larry-NC]

Originally Posted by Bama Rambler

The issue is that Resmed machines (and some others) use 24VDC instead of 12VDC, So you're still going to have to have some sort of power supply to change the 120VAC to 24VDC or use a buck converter to raise the 12VDC to 24VDC. And, they do draw almost 4 amps @ 24 volts, so that's 8 amps @ 12 volts.

Ahh, the OP didn't say that.

And, umm, that would be a boost converter.

[Bama Rambler]

You're right. I fixed it in the post.

[PenJoe]

Originally Posted by Bama Rambler

The issue is that Resmed machines (and some others) use 24VDC instead of 12VDC, So you're still going to have to have some sort of power supply to change the 120VAC to 24VDC or use a boost converter to raise the 12VDC to 24VDC. And, they do draw almost 4 amps @ 24 volts, so that's 8 amps @ 12 volts.

Dual 12 volt batteries wired in parallel will give you 12 volts. The same two batteries wired in series will give 24 volts. Maybe Larry can answer the question as to doing both on separate circuits with the same batteries.

[Larry-NC]

Originally Posted by PenJoe

Dual 12 volt batteries wired in parallel will give you 12 volts. The same two batteries wired in series will give 24 volts. Maybe Larry can answer the question as to doing both on separate circuits with the same batteries.

Not at the same time, Joe. But here's a solution which will provide 24 volts DC at up to 10 amps (enough for both CPAPs) for a whole lot less than $90.
https://www.amazon.com/Cllena-Waterp...cs&sr=1-7&th=1

There's a check box on this page for 5% off, dropping the price to $28.50

They have a bunch of models. Be sure to pick the 12v --> 12v boost, 10 A capability.

[Reprise]

Seeing that boost transformer prompts me to ask a theoretical question, especially since I see there's a 30A option on that item...

For those of us that use 2 x 6v in series to make 12v ...

Could the 6v be wired in parallel, and a 6v -> 12v 30A transformer be used to boost the entire camper (given appropriate fusing / circuit safeguards, allowing for loss conversion, etc?)

Goal would be to double amp hours -- or would it effectively be 'halved' back to what it is under a series connection?

I'm thinking there'd be no effective increase in AH, now that I'm writing about it, but wanted to ask the electrical gurus.