Using an inverter to power my CPAP

[Texas_incognito]

I drive a truck for a living. I have a Remstar M plus with C-flex. I have a 400 watt inverter. However, utilizing the cigarette lighter the most I can hope for from my inverter is around 100 watts. If I do NOT use the heated humidifier, will the CPAP machine function correctly on 100 Watts? My pressure is set at 15, C-flex on 3 at sea level. Thank you in advance.

[physicsbob]

100 Watts should be enough, but the Remstar M and humidifier will run directly off 12 Volts. The sponsor of this board sells a very well made cord with a cigaret plug for $23.75 that is made for that Cpap.https://www.cpap.com/productpage/respir ... -cord.html . This will draw less power than a inverter.

[archangle]

I drive a truck for a living. I have a Remstar M plus with C-flex. I have a 400 watt inverter. However, utilizing the cigarette lighter the most I can hope for from my inverter is around 100 watts. If I do NOT use the heated humidifier, will the CPAP machine function correctly on 100 Watts? My pressure is set at 15, C-flex on 3 at sea level. Thank you in advance.

If you use just the blower, not the humidifier, you should be OK on the inverter.

You may be OK with the humidifier, but it's complicated.

There are at least two flavors of M series humidifiers. In some of them, the humidifier runs off 120V AC. On later models, it runs off of DC.

Look on the back of the humidifier and see if there is one or two cords running from the power supply "brick" to the CPAP and the humidifier. (Not the cord running to the wall outlet, the cord or cords between the brick and your CPAP.)

If there are two cords, you have the AC powered humidifier. If there's just one cord, you have the DC version.

The AC version of the humidifier may not be safe to run on an inverter. It might damage the humidifier. I haven't seen any official statement from Respironics about that. Inverters tend to produce a non-standard "Modified Sine Wave" voltage that will damage some AC powered humidifiers.

If you have the DC version, it's probably safe to use the humidifier with the inverter.

If you use just the blower unit, an inverter should be OK.

My CPAP draws about 30 watts on the AC line even with the humidifier running, so you may have enough power to run the humidifier as long as it's the DC model.

If you use the DC cord, the Respironics M Series Provider manual says "When DC power is obtained from a vehicle battery, the device should not be used while the vehicle’s engine is running. Damage to the vehicle or the device may occur."

I might risk it myself, but I would not start the vehicle with the machine plugged in.

If you take the blower unit off of the humidifier, you have to have a little connector adapter that comes with the unit to hook up the hose, but lots of people lose it.

[retrodave15]

I have a pure sine wave inverter in my motorcoach that I use to power my sensitive devices, computer and cpap when I am not on shore power. This is the one I have and it is expensive, but well worth it. http://www.amazon.com/dp/B0010X5KPG/ref ... wo=&hvqmt=

The cheaper inverters use a modified sine wave that is ok for some things like a curling iron or a hair dryer, but could fry or damage a computer. I have this wired directly into the battery system as it will draw quite a bit of power of the coaches batteries.

[GumbyCT]

I drive a truck for a living. I have a Remstar M plus with C-flex. I have a 400 watt inverter. However, utilizing the cigarette lighter the most I can hope for from my inverter is around 100 watts. If I do NOT use the heated humidifier, will the CPAP machine function correctly on 100 Watts? My pressure is set at 15, C-flex on 3 at sea level. Thank you in advance.

Since there is a power loss when using any inverter it is advisable to use directly on DC. Turn HH to zero if it also works on DC if you can tolerate passover will allow the longest use in this manner.

[archangle]

The cheaper inverters use a modified sine wave that is ok for some things like a curling iron or a hair dryer, but could fry or damage a computer.

Strangely enough, computers seem to handle MSW better than most gadgets.

It seems odd that the electric heaters on some CPAP humidifiers have trouble with MSW, but it's really the electronic control circuits that cause the problems. ResMed says MSW will damage an S8 humidifier.

[vpdavid]

First of all, you have to know that your device can run on DC power or not....... if it runs on DC power then you can directly connect with your battery as well. 12V battery can be helpful to run such machines as well. If you use DC power then there is no requirement of any inverter. Main task of an inverter is converting current from DC to AC.

[chunkyfrog]

Any inverter that does not produce a pure sine wave, but is labeled as such,
is in violation of product labeling and safety regulations--
and the manufacturer can be held liable for damage.
Read the fine print very carefully--especially if the price seems too good to be true.
Peer UNDER any odd stickers--the truth is often hidden there.