VPAP Adapt SV and Long Distance Air Travel

Well, you knew I couldn't wait more than a day to see if I could tap into the collective experience and wisdom here!

I sometimes travel internationally. In researching options, I found the ResMed no longer supplies the DC-30 converter for either the VPAP Adapt SV unit, nor the AutoSet CS2 unit. They now recommend a DC to AC inverter with 150W continuous power:

http://www.resmed.com/us/patients_and_f ... c=patients

The only problem is that most airline power ports only supply 75W of continuous power. See the note titled "Will there be enough power for my device (how many watts can it handle)?" at the bottom of the following page:

http://www.seatguru.com/articles/in-sea ... p#adapters

So, has anyone else been able to power their Adapt SV using an airline power port? And if so, what did you use to do that? Or do I need to consider obtaining a battery pack for travel?

I think I will also call ResMed to see what they have to say about this.

John,
What are the DC voltage/current or voltage/wattage requirements for this machine?

timbalionguy wrote:... What are the DC voltage/current or voltage/wattage requirements for this machine? ...

Well, that's the funky thing about this, which is why I will call ResMed. The documentation notes:

AC input: 110–120 V and 220–240 V; 50–60 Hz; 60 VA
DC input: 30 V (DC-30 Power converter for portable operation via car DC power output)

The DC voltage requires a converter (and a special plug). AC power requires 60 VA (aka Watts). So, the 75W power of a power port SHOULD provide enough power. But, the battery guide notes the VPAP Adapt SV without humidifier should use an inverter, which provides 150W of continuous power and a modified sine wave. (Fortunately, it does not require a pure sine wave). It's documented on pages 7 and 13 of the english version battery guide from ResMed:

http://www.resmed.com/us/patients_and_f ... c=patients

Or course, it is possible this is just sloppy engineering / documentation, rather than an actual requirement.

I decided to email and then call ResMed on this. Glad I did it that way, since the Tech Services support person did not really understand the issues involved in this issue. Nor would I expect most folks in that position to have the background to understand it. Fortunately he understood my concern, took the information, will print and use the email to go investigate with the engineers. So, I should get an answer that I will share with everyone.

However, I am VERY impressed with how well ResMed did routing the email before I called. It went to the same person that received the call. As someone who deals with customer service issues all the time, I can not express how unusual that is. It is a very good sign. As a customer it definitely pleases me.

John

What I did was to not try to take the SV unit but for a few days would use an S8 with EPR set in CPAP mode with EPR=3 - easy to carry & while not as effective as the SV did the job well enough while I was traveling.

But I can understand anyone wanting to stay with their allocated machine even if it is rather heavy.

Good luck

DSM

If powering through an inverter, you will need more power than if you are powering through DC. The fact that thay quoted the power consumption in VA (volt-amps) tells me that this device may very well have cosiderably less than a unity 'power factor'. Devices like heaters and light bulbs have a power factor near unity, which means that they are using all the power they draw. Devices with a low power factor (a lot of electronic gear) draw more power than they need and then return it to the line. This causes them to appear like they are using more power than they actually consume. For use with an inverter, this means the inverter has to be overrrated.

We will assume 60 VA = 60W for a moment. 60 W at 30 volts requires 2 amps of current (there is no such thing as VA or power factor for DC). This is not a particularly big load. But 30 volts is a very odd voltage for any kind of power supply to provide. If using a DC-DC converter for battery operation, I would have to have this custom made, or build it myself.

If you have access to a bench power supply and a DC ammeter, I would suggest measuring how much current your unit draws at your rated pressure, and aim for a power source that can provide perhaps 33 percent more current. Another way is to hook two 12 volt gel cells and a 6 volt gel cell in series to get approximately 30 volts. (Don't know if that 30 volts needs to be regulated, but my guess is 'no'). Or 3 12 volt gel cells in series for 36 volts, with a simple series regulator to get down to 30 volts. Just make sure all three batteries are about the same AH rating, and are new (or the same age).