Cpap Machine - Page 2

tinglett · 02-01-2021, 11:20 AM

Quote:

Originally Posted by tinglett

would translate to about 4.5 to 4.8 Ah. That aligns with your measurement, and you have the humidifier going which is very impressive!

Whoops! Right as I hit submit I realized this does NOT translate to your measurement. You are measuring 5A continuous, which would be about 40 Ah over 8 hours. Doh! So yeah, that hurts, but is doable with your 170 Ah battery setup of course. Still, it's going to be on the order of half your power usage for the day, I think :(

Marine359 · 02-01-2021, 11:36 AM

Thanks Todd,
I should have stated 5a @ 12v, so it’s between brick and machine. Although the back of the machine says 6.67a @ 12v, but I suspect that is max for fuse. Based on your input, it seems the current draw savings of the 12v to 12v adapter is more significant than I thought versus the 120v brick. At only $37 on Amazon, I ordered today. it should pay for itself quickly, and I might save double digit amp hour consumption overnight. I have a clamp multimeter, so I’ll measure it when I finish electrical install.

tinglett · 02-01-2021, 11:48 AM

Quote:

Originally Posted by Marine359

and I might save double digit amp hour consumption overnight. I have a clamp multimeter, so I’ll measure it when I finish electrical install.

It'll be interesting to see if your results are similar. In the end, even if the numbers were the same I'd be happy to stick with my new DC-DC brick. I don't have much use for an inverter anyway as I haven't been using a laptop (tablet/phone instead) and we jettisoned the TV

.

Oh, also I installed 5mm barrel jacks in my USB ports that I use for 12v connections. I should see if I have a photo of that somewhere. That is now how I connect the cpap brick. Very convenient and they weren't too hard to add as the USB port has a pretty wide plate of plastic.

Marine359 · 02-01-2021, 12:17 PM

Didn’t know the mm USB ports could handle the current needed.

tinglett · 02-01-2021, 01:03 PM

Quote:

Originally Posted by Marine359

Didn’t know the mm USB ports could handle the current needed.

Unfortunately I don't have a photo to show exactly what I mean. I picked up these barrel jacks (2.1mm x 5.5mm) https://www.amazon.com/gp/product/B00JR591DG, and then I got other accessories to plug into them like this cigarette adapter: https://www.amazon.com/gp/product/B07P6PFNGP

The USB port itself isn't involved at all. I took advantage of the fact that my USB ports have a big plastic mounting flange. I drilled a hole in that flange and fastened the barrel jack in place, and then I crimped the barrel jack wires to the same 12v power source the USB ports were using. I believe this is on a 10A circuit. It was just a handy place to put a small 12v power port.

The only other device I have that uses this right now is a little 12v box fan that I can plug in and aim around the trailer. Works great for that, too.

RV-Travelers · 02-01-2021, 02:03 PM

Our 2016 Era 70A has a 12V power port in the rear. I plug a ResMed S9 into it (no humidifier) with a non-OEM 12V-24V adapter and it draws about 4.5 to 5 amp-hours over an 8-hour period.

This is the non-OEM adapter I use. Seems well made and has good reviews; I purchased a different one by the same manufacturer for running a laptop (12V to 19V). In either case, when we are plugged in to shore power I plug the devices into the 120V receptacles on the RV.

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

For backup purposes I bought a battery pack (never understood why they call it a solar generator) which has a built-in pure sine wave inverter. One reason I like it is it has DC outputs which are live without turning the inverter on. I'm able to get 3 8-hour nights out of it (with a little power left) using a DC output with the ResMed S9 set-up described above. It charges from an included AC adapter, 12V plug or a solar panel.

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

I also bought this 100-watt solar panel which can recharge the battery pack described above as well as other devices via a couple of USB ports. In bright sunlight with the panels aimed towards the sun it generate around 65 watts @ 19 volts.

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

al1florida · 02-01-2021, 05:20 PM

Quote:

Originally Posted by Marine359

Thanks Todd,
I should have stated 5a @ 12v, so it’s between brick and machine. Although the back of the machine says 6.67a @ 12v, but I suspect that is max for fuse. Based on your input, it seems the current draw savings of the 12v to 12v adapter is more significant than I thought versus the 120v brick. At only $37 on Amazon, I ordered today. it should pay for itself quickly, and I might save double digit amp hour consumption overnight. I have a clamp multimeter, so I’ll measure it when I finish electrical install.

If you use the 120V brick you will have to run an inverter. A 1000 watt inverter, just being on, uses about 1-2 amps, a 2000 watt inverter uses about 2, maybe 3 amps and that is before powering your CPAP. You could use a small 100watt or 150watt inverter that would use less power than the big inverters.

Fred 2106DS · 02-01-2021, 07:42 PM

Quote:

Originally Posted by Marine359

Thanks Todd,
I should have stated 5a @ 12v, so it’s between brick and machine. Although the back of the machine says 6.67a @ 12v, but I suspect that is max for fuse. Based on your input, it seems the current draw savings of the 12v to 12v adapter is more significant than I thought versus the 120v brick. At only $37 on Amazon, I ordered today. it should pay for itself quickly, and I might save double digit amp hour consumption overnight. I have a clamp multimeter, so I’ll measure it when I finish electrical install.

Jim, not sure which Phillips you use, I use this adapter for my Phillips Dreamstation. It has worked great for the last few years. I also see around a 5 AH draw when using the humidifier and 1 AH without.

Marine359 · 02-02-2021, 07:52 AM

Thanks Fred,
I have the older 60 series Phillips Respironics. Just purchased the adapter you have (but for the 60 series) from Amazon. Based on your info, I’ll be fine for a few nights before having to recharge main battery. Not a bad idea though to pick up a portable battery pack to run the cpap off-grid.

Marine359 · 02-02-2021, 08:01 AM

Hi Al,
You are correctomundo. That’s why I’m installing a 2000w Bluetooth inverter charger. The MM runs everything on dc except the roof air and microwave, which you never use while sleeping. I can just power-down the inverter before going to bed and run the cpap on dc adapter as you suggested. Thanks for your input.

BrewRy · 04-21-2021, 06:52 PM

Quote:

Originally Posted by Marine359

I have a Phillips system one cpap which draws about 5 amp when using the humidifier. I can’t really do well without the humidifier. There’s a cigarette lighter 12v power supply available on Amazon which should reduce watt hour consumption, but I can’t find any info on how much. Right now installing 170ah lithium, so I’ll have plenty of power. Wondering if the 12v power supply will reduce load enough to justify its purchase price.

Marine359:
My home machine has a humidifier, my travel machine does not. I wasn't sleeping well without humidification. I tried an Heat Moisture Exchanger (HME) device and now am comfortable on my travel machine without humidification. Initially, it feels like you have to breath a little harder, but somehow I didn't notice after a while. They are cheap and disposable (and also get nasty after a week about a week of use which is the time to toss it). Just a suggestion. Link below.

https://www.thecpapshop.com/heat-moi...l-cpap-machine

Marine359 · 04-23-2021, 06:25 AM

Thanks Brew,
I’ll try the HME on this ur next trip.