Using Cpap on DC for travel

[Tired Eyes]

I have a REMstar auto unit. On the back it says 12volt, 3 amps maximum, which I assume is at maximum output, so for anything less than maximum air output I assume it should consume less pwr. I picked up a generic DC cigarette lighter adapter, and the unit goes to start but immediately dies. I thought at first I had a defective adapter, so had the company sent a second but it does the same thing. I just ordered one from CPAP.com. The DC adapter they sell is considerably more money, so we'll see if that solves the problem. Anyone have any ideas why the generic adapter should not work? The plug size is identical, I believe it's 5.5 mm outside diameter, and 2.5mm inside diameter by 12 mm long. Don't quote me on this, but I measured it before I ordered.

Also, I know that the heated humidifier will not work on DC, but I would think just letting the air flow over the water would provide some moisture? Just curious if maybe heating some water to put in there would help. Not looking forward to dry sinuses during camping. Anybody have a solution to this?

Troy

[GumbyCT]

On start-up the motor requires a bit more current and something is prob limiting the current. You didn't say what you were connecting to so it could be that or the wire. Does it get hot? My guess is if you put a meter on your power source - you will see it dropping down, prob below 10 v.

The newest humidifiers will work on 12vDC however will draw more current. Passover mode is prob a good choice.

[CRMW]

The heated humidifier works in passover (non-heated) mode, there is not as much water vapor in the air.

A couple of thing to think about for the dc power:
1- How many volts did you have at the source?
2- If it was over the power rating of the adapter, the fuse in the adapter should have blown
3- Some adapters are negative tip (the center pin) polarity and some are positive tip.


What kind of machine do you have. Your signature has a remstar tank, but the humidifier is from an M-Series.

Chris

[Tired Eyes]

The heated humidifier works in passover (non-heated) mode, there is not as much water vapor in the air.

A couple of thing to think about for the dc power:
1- How many volts did you have at the source?
2- If it was over the power rating of the adapter, the fuse in the adapter should have blown
3- Some adapters are negative tip (the center pin) polarity and some are positive tip.


What kind of machine do you have. Your signature has a remstar tank, but the humidifier is from an M-Series.

Chris

the battery is at 12.7 V, fully charged. Maximum current, at least according to the manufacturers plate says 3 amps. I have run DC refrigerators that were 7.5amp with no problem, although they certainly run the battery down fast. I did check the fuse, and it is fine ( I thought of that too). If the polarity was reversed, I don't think I would get any lights, and the display does light up. It may just be that the wiring is not large enough to carry the amperage. The machine is not running long enough for the wiring to get hot. It basically just doesn't start. The lights go dim, and then restarts in a constant loop. It does kind of make sense that it's drawing more than the wiring can handle. I do have a new cord coming from CPAP.com, so guess I will see if it works better. The humidifier was for a different machine ( I originally had a straight CPAP) and then upgraded to a auto machine. So, I don't think the humidifier is different, but it definitely does not run off of DC. I'm guessing if I put some hot water in the humidifier before lights out, at least I will get a few hours before things dry up too much. Of course, the way I wake up throughout the night I can probably just add more hot water from a thermos!

Thanks for the response,

Troy

[Synergy Respiratory Care]

In response to use of your humididfier. If you use it with out turning it on and just putting water in it you will get whats called evaporation humidity which is by far better than going without any. Another alternative to buying the manufacture dc adaptor unit is buying a power inverter. You can get one for about 20 bucks and you can use it for other things aswell. I own a home medical respiratory company and tell patients to do that to save money. Laura RRT

[Tired Eyes]

In response to use of your humididfier. If you use it with out turning it on and just putting water in it you will get whats called evaporation humidity which is by far better than going without any. Another alternative to buying the manufacture dc adaptor unit is buying a power inverter. You can get one for about 20 bucks and you can use it for other things aswell. I own a home medical respiratory company and tell patients to do that to save money. Laura RRT

Hi there:

I actually have a power inverter in my camper, but bear in mind that power inverter's use power for the conversion process, that is to say they are not a very efficient, and also can be kind of noisy. I use mine to power my laptop, and it seems to work well for that purpose. I believe the humidifier uses something like 5 amps, so that's quite a bit and would kill most batteries in eight hours, especially when you factor both the humidifier and CPAP machine, which is another 3amps.

Along the lines of evaporation, I bet if I was to put a series of sponges or foam rubber in the water tank it would encourage more evaporation. I guess this is similar to how some home humidifier's work. It's basically just a fan and a wick. I'm thinking a series of channels to allow for greater air to water contact might work. What do you folks think? Would hate to wake up with a bloody nose from the dryness.

Running things off of DC, reminds me of the Apollo 13 mission and conservation! Every little amp adds up!


Troy