Is this 12v cigarette plug safe to use with plug in inverter?

[Beachcamper]

Recently I was diagnosed with the dreaded sleep apnea. Now I have to deal with how to plug the machine in while not on shore power. I have a basic system, 2 100ah AGM batteries in parallel, no inverter, propane fridge. My typical usage when off grid is 30 ah per day.

I have 2 options, buy a 12 v adapter for the Resmed Airsense 11 or not buy an adapter and use my plug in 300 watt inverter. I would use a plug at bedside that the dealer installed when I bought the RV in 2018. I took it off the panel to see how it was wired and it looks like they tapped into the existing USB port above. Do you think this will be safe to use with either option? The Resmed uses between 65-70 watts not using humidifier.

[ncitro]

Those look like pretty small wires. No idea what the CPAP pulls, I have heard its not much when the heater is turned off, but I would want something with larger wires. I dropped down into my front bay from under the bed (north south bed) and grabbed clean power from there with full sized wires to power my nightstand charging center. I would not use the inverter and would get the 12v supply for it. They usually step down from 120v anyway, so no sense to invert your 12 up to 120 just to step it back down to whatever the CPAP wants.

[bilco82]

Those look like pretty small wires. No idea what the CPAP pulls, I have heard its not much when the heater is turned off, but I would want something with larger wires. I dropped down into my front bay from under the bed (north south bed) and grabbed clean power from there with full sized wires to power my nightstand charging center. I would not use the inverter and would get the 12v supply for it. They usually step down from 120v anyway, so no sense to invert your 12 up to 120 just to step it back down to whatever the CPAP wants.

What size do you mean by "full size wire" and did you put an inline fues? If so, what size fuse? i plan to add
a 12v connection for my CPAP, too.

[Dave27]

I use a Morningstar SureSine 300 Watt power inverter. I wired it to run all the outlets. It works great. We run a CPAP, oxygenator, recharge laptops and phones every night.
Dave

[ncitro]

What size do you mean by "full size wire" and did you put an inline fues? If so, what size fuse? i plan to add
a 12v connection for my CPAP, too.

I ran 10 AWG, and tied it into a 12v fuse panel I added to the front bay for circuits I have added to the rig. The 10AWG was probably excessive, but I had it laying around and I wanted to be sure I would not have any issues with voltage drop or current rating.



https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[howson]

...buy a 12 v adapter for the Resmed Airsense 11 ... The Resmed uses between 65-70 watts not using humidifier.

Assuming a 13vDC source, the amperage being pulled from the battery is 70W / 13V = 5.38 amps. Assuming an 8 hour run (with no cycling) that's about 43aH pulled from the batteries. Insert an inverter and the power consumed will go up. How much it goes up depends on the efficiency of the inverter setup.

I'm not an expert on USB, but doing a bit of research it looks like the maximum a USB 2.0 port is designed to provide is .5A (1/2 of an amp). Chart below from https://lygte-info.dk/info/usbPowerS...tHow%20UK.html

What that tells me is the wiring provided by GD to that USB port may not be sufficient to sustain >5A over a long period of time. With a bit of forensics perhaps you can satisfy yourself that what is there IS sufficient.

However, if my conclusion is correct, running a robust wire (with appropriate size fuse--about 7A which is 125% of expected draw) as suggested by Neil ( ncitro ) above will draw the least power of the long term.

Howard

[Beachcamper]

howson ncitro Howard and Neil, I dug deeper into power requirements using the 12 volt adapter that Resmed sells for this airsense 11. I think it would be possible to use the plug at bedside. Unless I am not understanding it. As to going directly to batteries, I would need to figure out how to as I am not very comfortable with adding to existing system. But I am willing to learn if you all think my existing setup won’t work. My other option is to buy one of those Jackery units. The Resmed adapter is about $100.

Thanks to you both for your input.

[howson]

But I am willing to learn if you all think my existing setup won’t work. Thanks to you both for your input.

Maybe I'm not understanding?

Is the proposed setup to plug in the inverter to the outlet shown in post 1? If that's the case, plugging in a 300W-capable inverter to a circuit originally intended to support 2 ea USB ports capable of 1/2 of amp each (this assumes I'm correct with the research I've done...could be wrong) then this is a huge mismatch.

Using just power, 1 amp at 13V = 13W. The inverter is capable of supplying 300W. Can you see the problem?

Whether it's best (convenience vs cost vs hassle) to get a Jackery or pay a competent technician to wire in a 12v outlet (with the proper size wire and fusing) that will support the Resmed is a question only you can answer, Vivian.

If you're traveling through NW Florida, give me a shout.

Howard

[Reacher]

Most CPAP machines draw 30-60 watts. Check the mice type printing on the machine and or power supply to be sure. This article will explain.

https://housegrail.com/how-many-watts-does-a-cpap-use/

[ncitro]

howson ncitro Howard and Neil, I dug deeper into power requirements using the 12 volt adapter that Resmed sells for this airsense 11. I think it would be possible to use the plug at bedside. Unless I am not understanding it. As to going directly to batteries, I would need to figure out how to as I am not very comfortable with adding to existing system. But I am willing to learn if you all think my existing setup won’t work. My other option is to buy one of those Jackery units. The Resmed adapter is about $100.

Thanks to you both for your input.

Looks like using their power adapter it’ll draw 73 watts peak, at 12v that’s 7A. I doubt the wiring in place for the USB is large enough for that. I would get someone to run you a feed down to the battery, but another option might be to follow the usb wiring further up. Most all the 12v wiring is 14 gauge “zip” wire, and then it’s spliced to the small wires going to get device. If you can follow the USB wires further up and find those larger wires you might be good to use those. It would depend what else is on that circuit.

[Yoda]

Recently I was diagnosed with the dreaded sleep apnea. Now I have to deal with how to plug the machine in while not on shore power. I have a basic system, 2 100ah AGM batteries in parallel, no inverter, propane fridge. My typical usage when off grid is 30 ah per day.

I have 2 options, buy a 12 v adapter for the Resmed Airsense 11 or not buy an adapter and use my plug in 300 watt inverter. I would use a plug at bedside that the dealer installed when I bought the RV in 2018. I took it off the panel to see how it was wired and it looks like they tapped into the existing USB port above. Do you think this will be safe to use with either option? The Resmed uses between 65-70 watts not using humidifier.

Vivian
I run 2-CPAP's nightly. Here is a thread on how I did it and the parts that I used. Everything is working great https://gdrvowners.com/forum/operati...wer-in-bedroom

I used 10 awg wire to reduce voltage loss due the the long feed run. Be sure you 2 AGM's are fully charged and make sure the heating element is turned off in the CPAP if possible.

Safe travels
Keith

On edit - the USB wiring is not powerful enough, unless you unit wiring is larger than the 14 awg in mine and then the reduces wiring to the USB port itself.

[Beachcamper]

Maybe I'm not understanding?

Is the proposed setup to plug in the inverter to the outlet shown in post 1? If that's the case, plugging in a 300W-capable inverter to a circuit originally intended to support 2 ea USB ports capable of 1/2 of amp each (this assumes I'm correct with the research I've done...could be wrong) then this is a huge mismatch.

Using just power, 1 amp at 13V = 13W. The inverter is capable of supplying 300W. Can you see the problem?

Whether it's best (convenience vs cost vs hassle) to get a Jackery or pay a competent technician to wire in a 12v outlet (with the proper size wire and fusing) that will support the Resmed is a question only you can answer, Vivian.

If you're traveling through NW Florida, give me a shout.

Howard

Howard, sorry for the confusion. At this point forget that inverter, I would buy the adapter that resmed sells. It’s so infuriating I paid the dealer to install that plug and apparently only good for maybe a fan.

Going to check out the rest of the input on this post see if I feel comfortable doing this myself. If all else fails this summer, will not use the machine when overnighting at harvest hosts along the way north to Nova Scotia.

[Yoda]

Beachcamper
Vivian - there may be a simpler option. In you second photo (orange wire nut in picture) There appear to be blue romex (120v) and two sett of 14 awg wires . White with red stripe, and white with orange stripe.. It appears the white with orange stripe is feeding the power point plug through reduced wire sizes.. If you can wire the power point directly to one of the 14 awg wires you should be able to power your CPAP through the 12v adapter. The question is what are those two feed wires circuit rated at. You can trace them back to the distribution panel and see what else they power (wire color coding will be the same). It also appear the wires run through the floor and into the front bay. Maybe look there for them to.

On other question - what is the amp rating of the power point plug. Hopefully its 15a or better. It will be printed on it somewhere - probably the back. Also see if you can read any awg marking on the red and black wires going to that plug. Can you see if the tie to the 14 awg wire feeding the USB ports above. Maybe pull that and take a picture too to show how they tied in.

Of course you can always plug in the CPAP to that charging center with it off the wall and check the wires to see if they get hot, or blow the fuse in the distribution center. Its possibly your dealer used 14 awg to tie in with. If the did and tied to the 14 awg feeding the USB ports above you could possibly be good.

howson ncitro Howard and Neil am I thinking straight here that the 12v 14 awg\ should be able to handle 1 CPAP? My max power draw is 6.67A and 14 awg should work for that.

Vivian - what power ratings are shown on the back of your unit. Mine does not list a watts rating, but you mentioned 65-70 watts which is very close to what I have. The Blue Sea chart seems to indicate it should work http://assets.bluesea.com/files/reso...on_chartlg.jpg if she can get at least 14 awg to the power point plug.

Also do you happen to have a multi-meter and know how to use it?

Brainstorming here
Keith

On edit - to enplane my thought process - when I dove into this on my 220RKfor my CPAP's I found the USB ports were fed by a 12v 14 awg wire. However in tracing it back I discovered GD had lightning and the bath fan on the same circuit. It was a 15A circuit, but would have been maxed out. That's why I went separate. So it depends on what else is on the circuit that the dealer used and the wire gauge to the power point plug ant what they tapped on to.

[Beachcamper]

Beachcamper
Vivian - there may be a simpler option. In you second photo (orange wire nut in picture) There appear to be blue romex (120v) and two sett of 14 awg wires . White with red stripe, and white with orange stripe.. It appears the white with orange stripe is feeding the power point plug through reduced wire sizes.. If you can wire the power point directly to one of the 14 awg wires you should be able to power your CPAP through the 12v adapter. The question is what are those two feed wires circuit rated at. You can trace them back to the distribution panel and see what else they power (wire color coding will be the same). It also appear the wires run through the floor and into the front bay. Maybe look there for them to.

On other question - what is the amp rating of the power point plug. Hopefully its 15a or better. It will be printed on it somewhere - probably the back. Also see if you can read any awg marking on the red and black wires going to that plug. Can you see if the tie to the 14 awg wire feeding the USB ports above. Maybe pull that and take a picture too to show how they tied in.

Of course you can always plug in the CPAP to that charging center with it off the wall and check the wires to see if they get hot, or blow the fuse in the distribution center. Its possibly your dealer used 14 awg to tie in with. If the did and tied to the 14 awg feeding the USB ports above you could possibly be good.

howson ncitro Howard and Neil am I thinking straight here that the 12v 14 awg\ should be able to handle 1 CPAP? My max power draw is 6.67A and 14 awg should work for that.

Vivian - what power ratings are shown on the back of your unit. Mine does not list a watts rating, but you mentioned 65-70 watts which is very close to what I have. The Blue Sea chart seems to indicate it should work http://assets.bluesea.com/files/reso...on_chartlg.jpg if she can get at least 14 awg to the power point plug.

Also do you happen to have a multi-meter and know how to use it?

Brainstorming here
Keith

Keith, I will investigate further will try to trace those wires. My Airsense 11 shows 2.71 amps DC of output. Supposedly (without humidifier/heated hose) it’s more efficient than the airsense 10.

[ncitro]

Yoda Yes, thats basically what I suggested as well. Pretty much all of the 12v wiring in the rig starts off as 14 gauge, so if you follow the wiring back far enough you should find bigger wire. The question will be what else is on the circuit (probably the lights at least), but its worth a try. 14 Should be plenty for the CPAP, depending what else is drawing.

Beachcamper If you are near Chicago on your way up, let me know. If you stop by here (we will only be home until mid May when we head for Alaska) I can probably get you fixed up in ten minutes