CPAP Power From USB-C Wall Plug in 2023 Micro Minnie 2108FBS

[bcborn]

Hello all,

I have a Resmed Airsense 11 CPAP Machine that I am now taking camping. Up to now I have been powering the Machine via my 2000 Watt Xantrex and my 300AH Lithium Battery.

The CPAP used 25% of my battery overnight. when powered through the inverter. I bought the Resmed DC Adapter (with cigarette plug) and a USB-C to Cigarette Socket Conversion Cable. I plugged the Conversion cable into my 2023 2108FBS USB/USB-C Wall plate next to the bed and the CPAP would not power up. As with most of those wall plates, am I correct to assume they are 5volts for charging phones and the DC Adapter requires 12Volts.

To be sure the DC Adapter was good, I borrowed a Cigarette Socket with alligator clips from a friend. Attached the alligator clips directly to the battery and the CPAP worked. FYI; the power consumption dropped to 5% of my battery overnight.

The question I have is; can I replace the OEM USB/USB-C wall sockets for a different USB/USB-C wall socket that will still charge the phones and power the CPAP machine (12 Volts).

or

Is my only option to install a dedicated Cigarette Socket near the bed to plug in the DC Adapter's Cigarette Plug?

The Resmed DC Adapter has an input rating of 12volts 10Amps.

 

[Waterbug]

The USB to cigarette socket adapter is the issue. You are going from 5 volt USB to !2 volt cigarette adapter and then 12 volts back to 5 volts USB. You need the proper USB cable to go from USB wall plug to USB CPAP input. Going from 12 volts to 5 volts is simple but going from 5 volts to 12 volts requires over twice the current. Power = voltage X current.

 

[bcborn]

This is the adapter I bought; The CPAP has a Cigarette plug not a USB-C connection.

Amazon.com

I thought it would be a straight USB-C to Cigarette socket. Like alligator clips to Cigarette Socket. The unit I bought doesn't look like it has any circuitry to alter it's power output.

So my thinking after the fact, that the USB/USB-C wall outlet (Female) in the Micro Minnie would have been the issue. There is 12 Volts power to the wired side (back) of the Micro Minnie wall plug, but I have no way of measuring the the output directly at the USB-C Outlet.

I plugged the above conversion cable into the Micro Minnie outlet and the voltage at the cigarette plug dropped to 11.96 - 11.98V, unsure what the current output would be?

What's the solution?

 

[Waterbug]

Your problem is that the adapter you bought has an output of 3 amps/36 watts and your CPAP draws more than that. Since there is 12 volts at the back of the USB recepticle, you can replace it with a cigar lighter recepticle. There are several types available on Amazon. https://www.amazon.com/s?k=cigar+lighter+socket+with+mounting+plate&crid=31R964C2K2XMP&sprefix=cigar+lighter+socket+with+mounting+plate,aps,239&ref=nb_sb_noss_1. You may need trouble upgrade the associated fuse. EDIT: Ignore the sockets with USB connectors. EDIT#2: USB-C outputs 5 to 48VDC. USB-B outputs 5VDC. If your existing outlet is USB-B, the adapter you bought will only put out 5VDC. Replace the USB-B socket with a USB-C socket or cigar lighter socket.

 

[bcborn]

I pulled the plug from the Minnie to see if there were any details to output. The plug has both USB and USB-C, unfortunately, it only outputs 5 Volts. and 5 .4 Amps.

As you mentioned the USB-C socket and plug has a range of 5v to 48v,

After pulling the OEM Socket, it looks like there may be room in the front wall (depth) to house a cigarette lighter socket. As I cannot get in behind the front wall to secure the typical cigarette lighter socket which has a nut, I will have to find one that has a screw mount flange and mounts from the front.

I will have to research to see if those USB wall sockets are fused with a 10amp or 15amp fuse before tying in to that source.

Would changing out the current USB/USB-C wall Socket for one that outputs 12 Volts, (watts ??) fry the phone if it is plugged in there?

I found numerous wall plug on Amazon that are 12v with a various watt outputs.

As mentioned, the input of the CPAP Adapter is 12v 10A. On the front it says 90W. Assume a new USB-C wall socket would have to have a rating capable of 12v 90W min???

Lastly as mentioned my conversion cable only out puts 3amps and 36watts. Guess it too is of no use here.

 

[Waterbug]

USB-C sockets are supposed to be "smart" and determine the voltage required by the plugged in device. However, they can only supply the voltage provided to them. If attached to a 48 VDC source, they can provide 5-48 volts. If attached to a 12 VDC source, they provide 5-12 VDC. If attached to a 5 VDC source, they only provide 5 VDC. They are designed to provide "quick charge" to devices designed for USB-C. They will only supply 5 VDC to USB-B devices.
90 watts means that your CPAP draws 7.5 amps. 90÷12=7.5
EDIT: This looks like the socket you need. Amazon.com

 

[bcborn]

Thanks for that info. I will return the USB/USB-C to Cigarette Lighter Plug I bought and purchase the Cigarette Lighter Socket Plug you linked here.

I believe the current USB/USB-C Wall Socket is Fused with a 10amp fuse. In the fuse panel it only has fused for front 10amp rear 10amp.

For ease of hookup, I can remove the current +/- marrett attach the +/- of the Lighter Socket and re marrett.

Thanks again for your help.

 

[tomcat4u]

I had two different 12V outlets added to my 25 2108 FBS, one at the head of the bed next to the USB A and C outlets and one in the entrance way next to the service panel. That should solve your problem.

 

[bcborn]

Cigarette Lighter Plugs ??

 

[klook]

12v is always a cig lighter plug. Unless you go military grade or wire something in custom. USB C is the newest latest greatest. USB B is an oddball today, it was for printers, camera's, and a few other electronic devices. Most often they had a USB A on the other end of the cable. Go with what he spec'd for you and it will work fine. I hate the 12V cig plugs but they are still a necessary evil in my Class C.

 

[RVL895540]

We have two Resmed AirSense 11 CPAPs in our over bed cabinets. They are powered by two of the Resmed DC adapters. There is a cigarette lighter socket on the underside of the cabinet next to the bed, over the dinette. I removed the interior panel at the end of the cabinet above the dinette to expose the wiring and spliced into the 12 V wire going to the lighter socket. A hole was drilled through the partition into the cabinet over the bed. I put a 4 connector Anderson Powerpole distribution block

4 Position Power Distribution Block for 15/30/45A Powerpole Connectors

on the wall of the cabinet above the bed and connected the wire from the lighter socket to it using a Powerpole connector. The DC connectors from the Resmed power adapters were replaced with Anderson Powerpole connectors and they plug into the distribution block.

The USB ports in an RV are powered by 12V DC. I would not try to go from 12V through the USB port and then back to 12V to power the Resmed adapter(s). It is just not a good way to do things, even if it would work. You might splice into the 12V lines going into the USB ports and add connections to supply your Resmed adapters. Our DC lines have a 15 A fuse. In a year, the fuse has popped twice. I no longer use the cigarette lighter plug to charge our laptop computers while we are using the CPAPs.

Anderson Powerpole connectors are very good DC connectors, commonly used in amateur radio. They will carry a minimum of 15A in the smaller connectors as shown in the link. Higher current versions are available if needed. I unplug the Powerpole connector from the cigarette lighter socket going into the distribution block when the RV is not in use so that the Resmed adapters are not consuming any DC current.

We tried using the CPAPs powered by the inverter and found the battery drain was more substantial.

 

[bcborn]

As we didn't have a cigarette Light Plug in the trailer that was my next task.

I install the plug with a dedicated on off rocker switch next to the USB/USB-C and AC plug next to the bed.

I wanted to pull power from my newly installed fuse panel in the pass-thru. As there was horizontal blocking in the front wall at shelf level, I didn't want to have the exposed wire next to the bed, I ended up splicing into the 12V from the back side of the USB/USB-C plug.

 

[bcborn]

USB-C sockets are supposed to be "smart" and determine the voltage required by the plugged in device. However, they can only supply the voltage provided to them. If attached to a 48 VDC source, they can provide 5-48 volts. If attached to a 12 VDC source, they provide 5-12 VDC. If attached to a 5 VDC source, they only provide 5 VDC. They are designed to provide "quick charge" to devices designed for USB-C. They will only supply 5 VDC to USB-B devices.
90 watts means that your CPAP draws 7.5 amps. 90÷12=7.5
EDIT: This looks like the socket you need. Amazon.com

Something is going on here. I have 13.37 volts (lithium) at the back of the cigarette lighter plug, but the CPAP power light just flashes when the DC Adapter is plugged in.

When I have the CPAP plugged into a extension cable (cigarette lighter plug and socket) that is plugged into a cigarette lighter plug with alligator clips and plugged right onto the battery (13.37) the CPAP turns on.

I thought it might be a bad connection between the DC Adapter cigarette lighter plug (male) and the new cigarette lighter socket ( female).

So I took the wires off the back of the new cigarette lighter socket (female) and clamped the alligator clips with extension to the wires and the CPAP still would not operate.

Does it have something to do with wire size and the fact the 13.37 is on a 20 amp circuit???

 

[Waterbug]

Something is going on here. I have 13.37 volts (lithium) at the back of the cigarette lighter plug, but the CPAP power light just flashes when the DC Adapter is plugged in.

When I have the CPAP plugged into a extension cable (cigarette lighter plug and socket) that is plugged into a cigarette lighter plug with alligator clips and plugged right onto the battery (13.37) the CPAP turns on.

I thought it might be a bad connection between the DC Adapter cigarette lighter plug (male) and the new cigarette lighter socket ( female).

So I took the wires off the back of the new cigarette lighter socket (female) and clamped the alligator clips with extension to the wires and the CPAP still would not operate.

Does it have something to do with wire size and the fact the 13.37 is on a 20 amp circuit???

Is there any chance that the polarity is reversed? (+ and - wires crossed somewhere? Pay attention to reading + or - , when measuring voltage.)

 

[bcborn]

If it was backwards anywhere it would be at the splice behind the usb/usb-c wall socket.

Had a red and black out of it, so I assumed typical red was pos, black negative.

Switch was 3 terminal as has led. Black from splice to neg on switch out front neg on switch to neg at cigarette lighter plug.

Red from splice to line side of switch, out from load side of switch to pos terminal of cigarette lighter socket.

 

[Waterbug]

If it was backwards anywhere it would be at the splice behind the usb/usb-c wall socket.

Had a red and black out of it, so I assumed typical red was pos, black negative.

Switch was 3 terminal as has led. Black from splice to neg on switch out front neg on switch to neg at cigarette lighter plug.

Red from splice to line side of switch, out from load side of switch to pos terminal of cigarette lighter socket.

Have you verified the polarity at the female socket with a meter.

 

[bcborn]

Not yet. Is this correct, I will extent the neg from my meter to the battery neg and then touch the center terminal of the cigarette lighter socket with the red meter lead to see if I get my 12+ volts.

Will that determine correct polarity?

 

[bcborn]

Polarity is good, center terminal of cigarette lighter socket positive 13.07 volts.

Thinking it has to do with the male plug and female socket connection.

In the old days, getting a connection involved wiggling the plug. In some case it was trying a differently designed plug.

 

[bcborn]

Took the new cigarette lighter socket from wall and jumpered it directly to battery and the CPAP worked property.

We obviously have the voltage (13.3) at the new wiring in the front wall.

would it have something to do with amperage?

The USB/USB-C sockets in the front wall have 13.37 volts going in to them, but as they only put out 5 volts and under 50Amps, is there something in the wiring restricting amperage going to them.

 

[klook]

I have several 12v male plugs and I have found them all horrible at keeping a connection. I have 3 female connections in my RV and they have to be wiggled to make contact. I think it is the quality of the male plugs. Check in the male plug for a blown fuse....