inverter size for cpap??

my c-pap machine plugs into a 12 vold power source as long as I don't use the humidifier. if I was to use the humidifier I would want at leat a 800 watt inverter

 

There's several models of cpap around.
It would be best to look your unit over to find it's wattage requirements.
Size your inverter to match with a little leftover.

 

Schneider normally has a 180W limit on inverters, but if you have a CPAP machine it's 400W. I guessing that would be the size you need, not sure about the humidifier part.

 

You need to check with the manufacturer of the CPAP machine about the size rating of invertor needed for your particular machine. Factors that affect the draw include the pressure setting your doctor has prescribed (higher pressure more draw more watts needed).

Also you need to factor in whether or not you will be using the heat/humidification part. How high you set the humidification will also affect the amperage draw.

The manufacturer of my CPAP was GREAT when I contacted them through their website and explained why I needed information. They took a CPAP of my make and model set it for my pressure settings and humidification on a test bench and measured the amperage draw. They gave me a range of wattage for sizing a good invertor. You also need to check with the CPAP manufacturer if their machine needs pure sine wave or if it can run on modified sine wave 110-V power. Most invertors sold at truck stops are modified sine wave. Pure sine wave invertors are designed for running certain types of electronics often in boats and are a bit harder to locate.

You can over time mess up the CPAP machine using the wrong kind of invertor. I burned out the motor on my first CPAP using a modified versus pure sine wave invertor. But, it took 2 years to burn out the CPAP motor.

The other issue is making sure you have the proper battery capacity to handle that amperage draw for a full 8 hours if you are not going to idle or use an APU.

GOOD LUCK.. and sleep well.