# Dc To Ac Inverter Question



## pep_ (Apr 27, 2012)

http://www.campingworld.com/shopping/item/xpower-digital-micro-400-watt-inverter/31541

Has anyone ever used something like this? My wife has to use a CPAP breathing machine for sleep apnea. So far since we bought our OB this spring we have only camped at sites that have power so it has not been an issue. We are dry camping with friends this coming long weekend. I could leave the generator running all night if need be but another friend said I should look into one of these. If anyone has any experiences good or bad I would appreciate any information. Thanks


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## Tangooutback (Apr 16, 2010)

pep_ said:


> http://www.campingworld.com/shopping/item/xpower-digital-micro-400-watt-inverter/31541
> 
> Has anyone ever used something like this? My wife has to use a CPAP breathing machine for sleep apnea. So far since we bought our OB this spring we have only camped at sites that have power so it has not been an issue. We are dry camping with friends this coming long weekend. I could leave the generator running all night if need be but another friend said I should look into one of these. If anyone has any experiences good or bad I would appreciate any information. Thanks


Do you know how many amps the CPAP machine draws?


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## Insomniak (Jul 7, 2006)

Inverters are nice to have, but you need to size them appropriately. How many watts does the CPAP machine use? Determine the number af amps by dividing the wattage by 10 for a ballpark estimate. Multiply the number of amps by the number of hours the machine willl be in use and that will be the minimum number of amp-hours your battery will need to provide every night. Double that number to avoid completely discharging the battery & you will have a realistic idea of how many amp-hours the battery bank needs to provide.


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## pep_ (Apr 27, 2012)

Excellant info. Now one mod on my list is to change out my 1 stock 12v battery that came with my OB for 2 6v batteries. But in the short term do you know where I can find what what the amp/hours of my existing battery has? Would it say on the battery itself?

I don't know the amp draw of the machine yet. My DW has been searching for 2 days for the manual for it














. I am searching the interwebs for it as well.

Thanks guys


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## KTMRacer (Jun 28, 2010)

I use a CPAP and IMHO there is a far better choice and in my case also qualified as a health care reimbursement account expense.

Here is a link to the website.

Battery power solutions CPAP batterys

They sell battery packs and inverters specifically designed for CPAP machines. I have the battery pack and also the small inverter that works great with CPAP machines.

I have the C-222 battery pack, it will run my CPAP for 3 nights, can be recharged from AC, the trailer 12V or from your car. You can look up your CPAP and it will give you an estimated run time on the C-222 battery pack.

the inverter I have is the 150W sine wave inverter.

Give them a call with the CPAP you have and they will give you very good advice on what unit to purchase for your specific machine.

The C-222 also passes muster with the FAA etc. so you can transport it on an airplane as carry on. IIRC the biggest battery pack may not qualify, to large of a lithium battery pack, but they can tell you.

PM if you want more info.


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## JIMMY77 (Mar 5, 2012)

pep_ said:


> http://www.campingworld.com/shopping/item/xpower-digital-micro-400-watt-inverter/31541
> 
> Has anyone ever used something like this? My wife has to use a CPAP breathing machine for sleep apnea. So far since we bought our OB this spring we have only camped at sites that have power so it has not been an issue. We are dry camping with friends this coming long weekend. I could leave the generator running all night if need be but another friend said I should look into one of these. If anyone has any experiences good or bad I would appreciate any information. Thanks


Yes I do.
Have been for a few years now.
I have a 750 WATT INVERTOR from sams club that i plug into and it powers not only the air pump but in the fall and spring i use the heater for the water so as not to get a head cold.
you will need a 27 to a 31 series battery. I have AGM type.

92-105 amps.

call me @ 715-254-6611


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## pep_ (Apr 27, 2012)

Thanks KTM. I like this option. Can you run your CPAP machine directly off DC or do you have to run it through the inverter to the battery pack? I will have to check what model my wife's is to see if it has a DC input tonight.



KTMRacer said:


> I use a CPAP and IMHO there is a far better choice and in my case also qualified as a health care reimbursement account expense.
> 
> Here is a link to the website.
> 
> ...


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## KTMRacer (Jun 28, 2010)

pep_ said:


> I use a CPAP and IMHO there is a far better choice and in my case also qualified as a health care reimbursement account expense.
> 
> Here is a link to the website.
> 
> ...


[/quote]

pep

My CPAP has a 12V input. What I found is that it will typically run 2 nights on the above battery pack, then the CPAP will shut down early in night 3 because it's setpoint for low battery is pretty high. So if on the third night I run the CPAP on the above battery pack and inverter it will go night 3 and sometimes night 4. Apparently the Lithium battery pack has a lower cutoff voltage for shutdown.

Battery power solutions folk were very helpful to me, give them a call with your CPAP info and they'll probably be able to give you advice on what to get.


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## raynardo (Jun 8, 2007)

I, too, need to use a CPAP machine.

My solution was to buy the 12v power pack made expressly for my my machine, Resmed. I keep a 12v AGM battery under the bed connected to a battery charger. I can go almost three nights without having to recharge the battery. But when I'm connected to shore power the battery is automatically recharged. If I know I have to stay off the grid (boondocking) for more than three nights, I carry another charged battery.

I also have a solar system on the roof of my Obi as well as a generator on my trailer, so I'm pretty well covered.

HINT: If you use a inverter, you're wasting too much power on the inverter - just by turning it on, it draws the battery, even if nothing is connected to it. Using my Resmed system, I also must disconnect the battery leads when I'm not using the CPAP machine, otherwise I drawing down the battery.


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## Fanatical1 (Jan 9, 2006)

I own this same 400 watt inverter. Bought it from Costco year before last for $16.97 when they were blowing them out.
I would not recommend it because of a low voltage alarm it uses when the volts drop below 11.8. I found that on a longer run of wiring the voltage drops below 11.8 even though the battary voltage is higher. I took it apart and disconnected the alarm and still use it.

- My CPAP uses aprox. 45 watts with the heater off and 110 with the heater on. I leave the heater off
- I use the camper battery and have a seperate line for the Inverter, in my opinion the 12V plugs in the
camper are not designed for the draw of the inverter and CPAP together.


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