Which CPAP for camping.

[maverick2777]

My Remstar Auto has had 3 repairs since I purchased in Sept 2006. All faults have been error 87 with the replacement of the mother board. I went camping this weekend & ran it from my car deep cycle battery & the first night of camping it displayed error 45. I have given up on this machine, I think it's made for the home and not to take away on holidays & camping. Can anyone one suggest which CPAP to get for camping running on a 12VDC deep cycle battery. I only need 4-8CMH2O.
The GoodKnight 420G looks o.k., any advice ?

[WNJ]

Sorry you’ve had problems with your REMstar Auto.

When I had to go on CPAP, one of my top priorities was to select the one best suited to camping. After a lot of research, I chose the REMstar Auto. It has worked flawlessly for me for two years, including close to 100 nights running on 12-volts while camping.

I use the Respironics DC adapter (only about $25 from cpap.com.) When I’m in the RV, I plug it into a 12-volt outlet using a 12-volt extension cord. When I’m camping without the RV, I use a 12-volt female plug to battery-clamp adapter and a separate deep-cell battery. I use the heated humidifier as a passover when camping. As best I can estimate, the REMstar Auto draws only about 1 amp of power, when set at 10-14cm in auto mode.

Running directly on 12-volts should make no difference in the operation of the REMstar Auto (unless you reverse the polarity of the attachment to the battery.) It runs on 12-volts even at home when it is plugged into 120-volts. It has a built-in transformer which converts the 120-VAC to 12-VDC before it reaches the business end of the machine.

Assuming, however, that your experience has left you with a bad taste for the Respironics products, the PB 420 would be my second choice. ResMed machines would be my last choice for camping, as they are extremely sensitive to power input and the DC adapter is ridiculously expensive.

Wayne

[maverick2777]

After arriving home & plugging into 240Vac (Australia) the remstar is working o.k. I only experienced problems when running on the 12VDC deep cycle battery. The first half a dozen camping trips it has been working fine. I will continue to use the Remstar only at home & will now look at purchasing a PB420. The PB420 is alot smaller than the Remstar so it will be easier to take away on camping trips.
Thanks Wayne for your valuable input.

Preston

[billbolton]

ResMed machines would be my last choice for camping, as they are extremely sensitive to power input

No more so than Respironics or PB.

and the DC adapter is ridiculously expensive.

Less so than the damage that you can do a battery with any 12V powered flow generator by discharging it deeply.

The Resmed DC-12 adapter makes battery powering pretty much foolproof for Resmed machines but you don't need to use it of you are prepared to take the same chances that a users of other flow generators take on battery power.

Cheers,

Bill

[dunnwes]

CPAP.com has a couple of battery packs that look small and have plenty of power. They are both made by The Battery Geeks.

One has 150 amp hrs. https://www.cpap.com/productpage-advanced.php?PNum=2578

The other one has 222 amp hrs. https://www.cpap.com/productpage-advanced.php?PNum=2579

If anyone has use either one please let me know how they liked it and the hours used in between charges.

Wes

[Wulfman]

I've never used one of these, but if a person is going to be doing a fair amount of camping or traveling, I would think that something like these would be pretty handy.

https://www.cpap.com/productpage-advanced.php?PNum=2161

https://www.cpap.com/productpage-advanced.php?PNum=2573

Den

[maverick2777]

It was suggested to me today by a CPAP consultant to use a 150W Invertor to run the Remstar Auto when camping. 12VDC converted to 240Vac. He has experienced these sort of problems with Remstar & Goodknight when using a car battery. The GoodKnight tends to blow the fuse on the circuit board. The battery packs looks good but I have no room for it when camping. The 4WD has a duel battery system which I utilise for running my fridge & CPAP.

[engine 88]

I have used a Respironics series M machine with excellent results.I power it with a deep cycle gel marine battery with excellent results.I did this on Ossabaw Island off of the coast of Georgia.Usually 3 or 4 nights.This machine has about 1500 hrs on it.The only problem I have is that the air I'm breathing feels very cold as this is usually done in December or January. Anybody have an idea on how to warm the air?

[WNJ]

CPAP.com has a couple of battery packs that look small and have plenty of power. They are both made by The Battery Geeks.

One has 150 amp hrs. https://www.cpap.com/productpage-advanced.php?PNum=2578

The other one has 222 amp hrs. https://www.cpap.com/productpage-advanced.php?PNum=2579

If anyone has use either one please let me know how they liked it and the hours used in between charges.

Wes

Wes,

If you will read carefully, you will see that the rating for those batteries is not in amp-hours, but rather in watt-hours. Big difference.

Divide 150 watt-hours by 12 volts to convert to amp-hours and you get about 12.5 amp-hours for $325. My REMstar auto seems to draw about 1 amp. Theoretically, I could run my REMstar auto about 12 hours, but I suspect that in the real world it would power my machine more like 8 hours. It takes 5 hours to recharge and it would need recharging every day.

Divide 222 watt-hours by 12 volts and the second one is about 18.5 amp-hours for $425. At one amp draw, I doubt I could get two full nights use from this one without discharging it too far. It takes 8 hours to recharge from a full discharge.

These would be fine if you needed battery power for one night and could re-charge before using again. Ideal for using the CPAP on the red-eye flight. Not so ideal for camping.

For camping (when I don’t have the bank of batteries in the RV) I bought a deep-cycle battery at Wal-Mart for about $45. It has 75 amp-hour capacity. It will run my CPAP for a week of camping without recharging, though it would last longer if it were not discharged more than about half (~ 40 hours of CPAP) before recharging. The down-side is that it weighs more than 40 pounds and I need to take reasonable precautions against spilling battery acid.

Bill,

To my way of thinking, more than three times the price = ridiculously expensive.

ResMed 12-volt adapter - $79.99

Respironics 12-volt adapter - $24.95

I’m not sure about the machines you have in Australia, but the ResMed machines in the USA appear to be more sensitive to power than the Respironics or PB machines. An example from the cpap.com page for the 12-volt adapter: “This is the only product that you should use to power the S8 machines from a DC source, unless you also use a heated humidifer. Then you will need a Pure Sine Wave DC Inverter. Other cables may fit but will blow out the S8 power supply (no kidding, we have found out the hard way). The polarity is different from most 12 volt cables and the converter provides needed power smoothing.” I found similar warnings on the ResMed web site back when I was researching this question.

I have used my REMstar Auto and $25 Respironics 12-VDC adapter for many hundreds of hours while camping. No need for special “power smoothing” like the ResMed.

And, unlike the ResMed, I can use my REMstar and heated humidifier with any 12-VDC to 120-VAC inverter with a minimum 300 Watts capacity; I am not limited to using a very expensive pure sine wave inverter.

Maverick,

The only downside to the inverter route is that it is inefficient to change 12-VDC to 240-VAC then back to 12-VDC (this last inside the machine.) Since you have a way of recharging the battery, this would not appear to be an issue for you.

Wayne

[Guest]

more info here: sleepapnea.respironics.com/accessories/dcpower.aspx

[billbolton]

To my way of thinking, more than three times the price = ridiculously expensive.

The Resmed DC-12 adapter isolates the output side from the input side and also provides active power management electronics for voltage regulation and noise filtering. There are many sources of 12V DC power around in the world and the power "quality" varies very widely across sources.

The DC-12 also enables using the Resmed machines from DC power sources up to 24 volts.

Its a completely different thing to the Respironics "cord" which is entirely passive.

I’m not sure about the machines you have in Australia

Resmed machines are basically the same everywhere in terms of the electronics platform.

but the ResMed machines in the USA appear to be more sensitive to power than the Respironics or PB machines.

They are not.

As I said previously, if you know what you are doing with electrical systems, you can connect up a Resmed machine directly to a 12V power source and take exactly the same risks that a Respironics or PB user takes in doing that.

The difference with Remed is that for those users who know nothing about electrical systems, the DC-12 provides a foolproof way of making DC power workable under just about any conditions (not just ideal conditions).

Cheers,

Bill