CPAP / APAP 12v and 24v conversion ?????

[nunyadamn]

Originally Posted by TCNashville

We have these and very happy with the light. As close to the old 12V and only 1/10th the power. Available on Amazon as well.

https://www.ebay.com/itm/GRV-T10-921...cAAOSwPh5ZHwJ6

I just got a couple of those. I was looking for something more warm/yellow like the incandescent bulbs. Also, they were a little brighter than the incandescent which isn't horrible but when you look at them I felt they sting the eyes more than the incandescent bulbs. We have one light right at eye level over the sink and it was blinding.

[Bendmac]

Greetings!

My wife and I both use CPAPs and we recently were able to get our own individual ResMed AirMini systems. The Mini is MUCH more portable, and, with not using a powered humidifier (it uses a humidifying filter in the hose), they consume far less power.

Looks like there a couple of ways to power these when dry camping and not hooked up to shore power:

-Use the (expensive) 12v-24v converters
-Go with a 12v-110v inverter system

Our son-in-law, who works at an RV dealer, was able to get us a Zamp 600w Pure Sine CPAP inverter along with the power head that has two 110v outlets. We currently use (2) 6v deep cycle batteries on the trailer and have installed a single 40w solar panel on the roof...we may add to that later to up the wattage. Trailer is a 24 FBS.

Now THIS is where I get a bit confused...you could put what I know about electricity and loads and such in a thimble!

-The Mini's user manual shows "typical power consumption" as 6.3w, "peak power consumption" as 27w and "standby power consumption" as 1w, per machine.

(I've attached a photo of the power supply which shows slightly different input/output numbers as far as amps, but nothing drastically different than what follows).

Now, knowing that batteries and load are measure in "amp hours", I'm assuming that one must convert watts to amps:

-6.3w =0.057 amps
-27w = 0.245 amps

So if my muddled thinking is right:

-6.3w = 0.057 amps x 8 hours = 0.456 amps, x 2 machines = 0.912 amps or a little less than 1 amp for BOTH machines over an 8-hour period, correct?

-27w = 0.245 amps x 8 hours = 1.96 amps, x 2 machines = 3.92 amps or a little less than 4 amps for BOTH machines over an 8-hour period, correct?

Am I barking up the right tree here as to battery load and consumption? If so, even with running lights, water pump and a few other 12v accessories, and having the solar panel to at least provide SOME sort of recharge, are we going to be OK for 4-5 days?

Finally, if anyone has some photos detailing how they set up a similar-type system in a front bedroom Jayco and are willing to share, I would greatly appreciate it!

[Danjo61]

I just bit the bullet and bought this Inergy Kodiak Portable Solar Generator (solar
rechargeable). I too have a 24v cpap and 2 Renogy 100 watt suitcase solar panels. Of course no heated water or heat in tube and using the 24v to 12v cigarette adapter. I am curious if this will work because Lithium-Ion batteries can be discharged more with use. I have yet to try this setup. I plan on using it on my pontoon boat as well - it has 200 watts flexible panels on the bimini enclosure.... Thoughts?


SPECS:
Internal Battery: 1,100 Watt Hours (90 Amp Hours, 12.6 Volts), Lithium NMC
Battery Life Expectancy: Up to 2,000 Cycles or 10 Years
AC Inverter: 1,500 Watts Continuous, 3,000 Watts Starting Surge. Pure Sine Wave
Charging: 600 Watts Maximum Input, 2.5 Hour Recharge Time at Maximum Input
Battery Expansion: Yes, Accepts Any 12V Lead Acid or AGM Deep Cycle Battery
Weight: 20 Pounds
Dimensions: 16″ Wide x 15″ Tall x 8″ Deep
Operating Temperature: -15°F to 150°F
Battery

Cell Type: Lithium-Ion (NMC) Battery.
Peak Capacity: 1,100 W continuous for 1 hour, 3,000 W peak.
12.6V DC, 90 AH.
Up to 2,000 charge cycles.
Charge at least every 6-months.

Inverter

Pure Sine Wave, 1500 Watt Continuous, 3,000 Watt Surge.
110 VAC, 50Hz ± .5Hz.
High efficiency, Ultra High Frequency Design. - Commercial Operating Range, -15°F to 150°F.

[SloPoke]

Stacy and I are newcomers to the CPAP discussion, her Resmed AirSense 10 is shipped this week. I have read this thread two times now and see what many of you have done to power yours while boondocking. Most of our travel in the Seneca is boondocking!

I see that Don is boosting the 12v to the 24v the unit requires and I see the overall draw on those DC to DC converters is about 5A when the unit is at maximum settings. As his math calculations are solid, I am considering something different.

First, Our bedroom is almost 32' away from our house batteries, I can buy another set of Sealed AGM batteries to power the CPAP and install them in the compartment below our bedroom for a few dollars more than the wiring it will take to get to the bedroom slide. So given that -

Instead of two new 12v Batteries in parallel to be able to store enough AH to run the 12-to-24v converter, why not wire the two batteries in series and power the Resmed directly from the batteries? The 5.6AH the 12-to-24v converter draws at 12v would only be 2.8AH at 24v (actually much less when you take out the power factor loss of the converter). Buy a dedicated NOCO Genius 15A 24v charger for the CPAP batteries and the charge time is reduced to 2.1 hours.

Since we usually have our genny run a couple of hours each day anyways, we will always be charged for the next couple of nights. This configuration takes out the inefficiency of the 12-to-24v converter which is at best 87% efficient.

[Bassdogs]

You guys are a lot better husbands than I. I think it is malpractice to sentence someone to strap on a C^ap machine just to keep a partner from snoreing. The way the world seems to be going we will have 50% of adults sleeping with one of these dreaded machines. For anyone who must use one for a serious medical condition, I totally understand. No judgement intended toward anyone for any reason who use one of these things. Its just a petpeeve of mine that you pretty much can't see a doctor for anything from a routine check up to a broken arm without being ask if you've taken a sleep exam.

Yes, I snore and have all my life. I also have a spare bedroom and will move into it before I get strapped to a machine.

[Bookemdanno]

Originally Posted by Bassdogs

You guys are a lot better husbands than I. I think it is malpractice to sentence someone to strap on a C^ap machine just to keep a partner from snoreing. The way the world seems to be going we will have 50% of adults sleeping with one of these dreaded machines. For anyone who must use one for a serious medical condition, I totally understand. No judgement intended toward anyone for any reason who use one of these things. Its just a petpeeve of mine that you pretty much can't see a doctor for anything from a routine check up to a broken arm without being ask if you've taken a sleep exam.

Yes, I snore and have all my life. I also have a spare bedroom and will move into it before I get strapped to a machine.

Sorry...couldn't resist responding to this...if nothing else, but to educate some folks.

For some it's not just about keeping us from snoring. The DW snores WAY more than I! It just means that she's actually breathing at night when she sleeps.

The DW convinced me to go to the Dr. about 4 years ago because I was always tired...I mean always tired...even from the time I woke up in the morning...and the only reason I agreed to go was because I feel asleep at a red light on the way home from work one night. I was 37 years old and 205 lbs...and probably in the best shape of my life!

I had the usual blood work done and had an elevated red blood cell count...Dr. told me to have a sleep study done and apparently I sleep so deeply that for every 2 mins of sleep, I was only breathing about 20 seconds. Alas the CPAP continually forces air into my lungs and keeps me breathing at night. Now...the Dr. said that I won't necessarily die from this, but that it will but additional stress on my heart and would likely end my life sooner rather than latter!

Just my $.02 cents for those that don't know!

[SloPoke]

Originally Posted by Bassdogs

You guys are a lot better husbands than I. I think it is malpractice to sentence someone to strap on a C^ap machine just to keep a partner from snoreing. The way the world seems to be going we will have 50% of adults sleeping with one of these dreaded machines. For anyone who must use one for a serious medical condition, I totally understand. No judgement intended toward anyone for any reason who use one of these things. Its just a petpeeve of mine that you pretty much can't see a doctor for anything from a routine check up to a broken arm without being ask if you've taken a sleep exam.

Yes, I snore and have all my life. I also have a spare bedroom and will move into it before I get strapped to a machine.

If it were just for snoring???? then I might be in agreement with you...

If it is about blood-oxygen levels dropping below 70% while sleeping, respiration levels going low and occasionally stopping breathing??? A different story then.

[Bassdogs]

Originally Posted by SloPoke

If it were just for snoring???? then I might be in agreement with you...

If it is about blood-oxygen levels dropping below 70% while sleeping, respiration levels going low and occasionally stopping breathing??? A different story then.

No argument there are valid medically necessary uses of these things. But in the recent years the use has skyrocketed and are prescribed to the majority of people who take the test. Whatever, but the people getting them but not using them got so high that most if not all of the machines self report usage levels not only to doctors but also the insurance companies who are picking up the tab. If you don't use the machine a certain % of the time they will stop paying for them. My point is not that they are not necessary but that they are terribly over prescribed and when the user finds them a pain to use, they end up getting stuck in a closet. In recent years "Sleep Specialists" have been cropping up everywhere and a vary high percentage of people who are tested are recommended for a machine. As insurance companies start cracking down, my guess is that the testing protocol will tighten up.

This probably needs to be a separate thread since the word CPAP is a topic in at least 3 of the currently active threads.

[RMartin]

Resmed makes a dc converter for the 24v device. I ran 10ga wire from batteries to the closet by bed. We have boondocked for a week without problems. We did run the generator for about an hour per day to operate other appliances. The literature from resmed states that their inverter will operate the cpap and water heater but I found that if I used the h5i the cpap would reboot every few minutes. I sent the first converter back thinking it was faulty but the replacement did the same thing. It will work fine without the water reservoir.I also tried the converter while plugged into shore power and it would still kick off so I know it was not a battery problem. You can turn the heat off and just run through the reservoir which will still add moisture.

[SloPoke]

Originally Posted by RMartin

Resmed makes a dc converter for the 24v device. I ran 10ga wire from batteries to the closet by bed. We have boondocked for a week without problems. We did run the generator for about an hour per day to operate other appliances. The literature from resmed states that their inverter will operate the cpap and water heater but I found that if I used the h5i the cpap would reboot every few minutes.

The DC converter you describe is the same as what I referred to as the 12-to-24v converter. It draws a max of 5.6AH according to the technical literature from the manufacturer. Like you, we generally run our generator for a little bit each day to recharge our coach batteries from the day before's use (we use the Energy Command 30 in auto mode to monitor our batteries and keep the genny from running in quiet hours)

We are looking at how we can eliminate the 12-to-24v converter and the extra power that it uses (about 13% of the power it uses is loss during the conversion) We also want to isolate the CPAP power from the coach power.
Our furnace can draw 8.0AH by itself, add that to the other appliances AND the CPAP and it can comes very close to a full battery discharge cycle (without going into a deep cycle - but close) Getting 13% better life on a days charge is pretty significant.

[Mustang65]

I have no clue as to how much you can afford, but if I owned a 24Volt CPAP unit, I would purchase an older 12Volt model (mine is 12Volt/5Amp - Respironics System One with humidifier). Then sell the 24Volt model. The path of least resistance, my favorite path, or go the last suggestion at the bottom of the page... but read on...…...

It sounds like you have a regular 12Volt 85Ah standard RV/Marine battery. If that is what you have, scrap the 85Ah and get (2) 100Ah RV/Marine batteries, and hook them together. Not expensive and will give you 100Ah to use with 50% rule ( 200Ah/2=100 useable Ah's).

Your furnace will probably only run 20 minutes out of each hour and I would think 12 hours would be sufficient for the calculation. So, 20 minutes * 12 times it will run in 12 hours=240minutes of run time each night. 240 minutes /60 minutes = 4 (hours) * 8Ah = 32Ah's total for the furnace.

Going by 5 amps (Max) for the CPAP machine = 5Ah *10hours = 50Ah total for the night (40Ah's if you only sleep 8 hours). So between the 2 big time Ah users you have 82Ah's (10hours of sleep). You have 18Ah's to play with.

If you have the room, a third 100Ah battery would take any fears of not having enough Ah's to meet your overnight 12Volt requirements. That would give you an extra 68Ah's to watch TV with or get the 24 to 12VDC to DC converter with power to spare.

I have seen my CPAP for sale on some of the re-sale sights. Check my math please a bit tired this afternoon.

Just a thought
Don
My Registry

RVing with SOLAR

[SloPoke]

Originally Posted by Mustang65

I have no clue as to how much you can afford, but if I owned a 24Volt CPAP unit, I would purchase an older 12Volt model (mine is 12Volt/5Amp - Respironics System One with humidifier). Then sell the 24Volt model. The path of least resistance, my favorite path, or go the last suggestion at the bottom of the page... but read on...…...

In our case... we don't get a choice. These things are leased to us by the durable medical equipment company - paid for by our Health Insurance. We get what they send us based on the doctors recommendation

Originally Posted by Mustang65

It sounds like you have a regular 12Volt 85Ah standard RV/Marine battery. If that is what you have, scrap the 85Ah and get (2) 100Ah RV/Marine batteries, and hook them together. Not expensive and will give you 100Ah to use with 50% rule ( 200Ah/2=100 useable Ah's).

Actually - we have 4 batteries in parallel, they are 95AH each, so we have 380AH of capacity. But I must note, we have extra 12v loads that we have to consider too...

Originally Posted by Mustang65

Your furnace will probably only run 20 minutes out of each hour and I would think 12 hours would be sufficient for the calculation. So, 20 minutes * 12 times it will run in 12 hours=240minutes of run time each night. 240 minutes /60 minutes = 4 (hours) * 8Ah = 32Ah's total for the furnace.

A great deal of our camping is above 5,000Ft. We are lucky if our 35kBTU furnace only runs 20 min/hour. It is often in the 20's F overnight and we set the furnace at 50 for our dogs. The burner cycles a lot, but there are times that the fan motor has not cooled the heat exchager of the furnace enough to turn the fan off - before it calls for heat again. When we are in a place with AC power, we augment the furnace with three space heaters, but then the furnace cycles at about 25% of the time running.

We also have other 12v appliances we are running on our House Batteries.
We have a wired network in our Seneca. Our outdoor LTE radio and our Network Router/Switch is powered by POE that is 12V powered. We also have a DVR running our cameras overnight (to watch the Elk,Deer,Bear,Racoon going rummaging thru our campground at 3AM)

The DVR is about 1.5AH and the network is 1.25AH = about 30AH overnight added to the other stuff that Stacy runs on the Inverter into the evening and morning TV, DirectTV Satellite receiver and then the coffee maker in the AM before everyone else might wake up. The total AHload on the house batteries is currently well below a full battery cycle, but adding the CPAP is going to push it further. that is why the two additional battery strategy is being considered, but without the 13% Power Factor loss of the adapter.

Originally Posted by Mustang65

Going by 5 amps (Max) for the CPAP machine = 5Ah *10hours = 50Ah total for the night (40Ah's if you only sleep 8 hours). So between the 2 big time Ah users you have 82Ah's (10hours of sleep). You have 18Ah's to play with.

If you have the room, a third 100Ah battery would take any fears of not having enough Ah's to meet your overnight 12Volt requirements. That would give you an extra 68Ah's to watch TV with or get the 24 to 12VDC to DC converter with power to spare.

I have seen my CPAP for sale on some of the re-sale sights. Check my math please a bit tired this afternoon.

Just a thought
Don

[Mustang65]

Originally Posted by SloPoke

In our case... we don't get a choice. These things are leased to us by the durable medical equipment company - paid for by our Health Insurance. We get what they send us based on the doctors recommendation

Find a 12Volt model, contact your doctor and have him write a script for that make/model. If he will not (kick-backs) find another doctor to write the script and cancel the first doctors selection. These devices do the same thing. If you find one on the internet that is 12Volts and inexpensive, buy it, and send the current one back. It is your choice not his.

Actually - we have 4 batteries in parallel, they are 95AH each, so we have 380AH of capacity. But I must note, we have extra 12v loads that we have to consider too...

Sorry, you only have 190Ah's not 380Ah's. 50% rule

A great deal of our camping is above 5,000Ft. We are lucky if our 35kBTU furnace only runs 20 min/hour. It is often in the 20's F overnight and we set the furnace at 50 for our dogs. The burner cycles a lot, but there are times that the fan motor has not cooled the heat exchanger of the furnace enough to turn the fan off - before it calls for heat again. When we are in a place with AC power, we augment the furnace with three space heaters, but then the furnace cycles at about 25% of the time running.

We also have other 12v appliances we are running on our House Batteries.
We have a wired network in our Seneca. Our outdoor LTE radio and our Network Router/Switch is powered by POE that is 12V powered. We also have a DVR running our cameras overnight (to watch the Elk,Deer,Bear,Racoon going rummaging thru our campground at 3AM)

The DVR is about 1.5AH and the network is 1.25AH = about 30AH overnight added to the other stuff that Stacy runs on the Inverter into the evening and morning TV, DirectTV Satellite receiver and then the coffee maker in the AM before everyone else might wake up. The total AHload on the house batteries is currently well below a full battery cycle, but adding the CPAP is going to push it further. that is why the two additional battery strategy is being considered, but without the 13% Power Factor loss of the adapter.

Decision time!!!! What is more important CPAP machine or watching video of animals in the dark, a network router running all night. Not sure as to why? Your outside cell signal booster? After hours? I take it the Satellite receiver is on all night.. Electric Coffee pot, especially on the depleted battery in the morning? Boil water on the stove and pour it into the coffee basket of the electric coffee pot. Coffee will taste the same and your batteries will love you!

Based on the above list of battery discharge devices that are used daily ok nightly... I would venture to say that your batteries are well below the 12.2VDC level in the morning. Which shortens the useable life of a battery each day that this is repeated. So, new you may have had useable 190Ah's, but each time you drop that voltage, like I believe you do, that 190Ah's drops to a new lower amount. So, maybe in a year with that pattern and throw in a factor for ageing (just like us), you could be at 170Ah's or less. Without testing... who knows.

I doubt very much that your batteries are recharged to 90% each day.



Questions:
- Are all your batteries the same mfr date?
- Did you add more batteries after the original one was in use for more than a few months?
- Have you ever killed the batteries?
- Do you monitor the battery voltage?
- Ah monitor?
Batteries water level always topped off?

All important questions about your past power usage that determine your future power!

Time to prioritize your Ah's. Turn off the DVR and watch old reruns of the animals at night. Boil your water for coffee. May not sound like much, but they all add up.

Just my thoughts
Don
My Registry

RVing with SOLAR