Resmed Airsense 10 Autoset with AC inverter

[Possum]

Greetings fellow hose-heads,

Does anyone have experience running their Autoset 10 Autoset off a deep-cycle 12-V car battery (55 Amp-hours), using a DC-to-AC inverter? The inverter is pure sine-wave, rated at 400 W (surge up to 800 W).

I've found conflicting information online - one area of Resmed's site (Travel information) says that an inverter can be used with any of their machines, provided it is rated at 150 W or more, but their Battery Guide says that the A10 Autoset should be used with a DC converter running directly to the battery, so I'm confused.

We are having an overnight power outage soon, and I'm trying to plan for it without spending $300 on a CPAP battery. I already have the deep-cycle battery and inverter for tailgating.

[Gideon]

Running DC from the battery thru the ResMed DC power cord is more energy efficient. As long as it is a full sine wave generator, you should be good. I do recommend that you turn off the humidifier and heated hose to preserve battery power.

[jaswilliams]

There is no need for a full sine wave Inverter as the switch mode power supply of the Resmed will solve your issues. If there is going to be a longer outage than 1 night or you plan going camping with your machine then the Resmed DC to DC adapter is more efficient than an inverter and I would recommend purchasing that but it does retail at about $80

[Possum]

Running DC from the battery thru the ResMed DC power cord is more energy efficient.  As long as it is a full sine wave generator, you should be good.  I do recommend that you turn off the humidifier and heated hose to preserve battery power.

That's what I thought, so I tried it last night as a test run. After only 30 mins the inverter started beeping with the Fault light on, so I moved my machine to my usual wall plug. This morning I checked the battery power and it was still 61% - inverter should not have alarmed until it hit around 30%, so I'm not sure why it was alarming...

I did lower my humidifier and heated hose settings, but even if I had those maxed out, that would be a current draw around 5 amps, and thus the battery at 55 Amp-Hours should have lasted 11 hours, or at least 10 hours if you factor in the 10% loss in efficiency using the inverter.

I just don't get it

[dwd1249]

When I used a full sine wave I would get 2.5 nights without humidifier on a 55ah. I got the RedMed 12v cord which is also smaller then the inverter to pack. Don't know how long it lasts as where I use it they run a generator in the daytime and evening evening so I recharge the battery.

[SarcasticDave94]

I've heard that an inverter would be an inefficient method as it converts from DC to AC (from a DC battery), consuming some power itself. If it were myself, I'd get the ResMed DC cord and go that way. For that time on DC, I'd set both heated hose and humidifier to Off. This would be expected to give you the most run time on a battery.

[jaswilliams]

I have just spotted on Amazon a clone DC-DC adapter KFD 24V DC Adapter in Car Charger Vehicle for only $32.95

[pabmd]

The Airsense 10 Autoset uses about 80 watts of power. At 12 volts that equals about 6-7 amps. Thus, a 55 amp hour battery would theoretically last up to 7.8 hours. HOWEVER, the actual amp hour rating is non linear and at a constant draw of  6-7 amps on a 55 amp hour battery will be about 60% of the stated amp hour rating giving you an approximate run time of 4.7 hours. This run time will be further shortened by temperature below 70 degrees.

A good inverter does use some power, but generally only 1-2%. 

I have run my Airsense Auto 10 with the humidifier and heated tube on auto in my camper. I have 160 amp hours. I can run it all night with a fan on, but my batteries are significantly discharged (11.6 volts) in the morning.

Be careful using any 12 volt adaptor. The problem is not the adaptor, but if you plug it into a 12 volt outlet in a car or camper, the wiring to the 12 volt plug may not be adequate to carry the 6 to 7 amps for prolonged periods of time. I burned up a Dream Station using their approved adaptor. Make sure the gauge of the wire supplying the 12 volt outlet is adequate. Depending on the distance to the batteries it should probably be 16-18 gauge minimum.

[RayBee]

You may want to check out the ResMed Battery Guid to help with your calculations. You may wish to drop the heated hose at least - it may help with run-time you want to get from your batterie(s).