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artluvr · 11-05-2014, 08:52 AM

We have recently changed over from a 5th wheel to a motorhome. We are going on a short caravan where we must boondock. The issue is I need a CPAP breathing machine to help my sleep apnea. We may not run the generator overnight. I thought we had an inverter, but I do not know if and how that will give me power through the night. I have a 12V to AC outlet adaptor but that doesn't seem to work with the motor off. Any help out there?
Tim Janicki

FlyingDiver · 11-05-2014, 08:59 AM

You're going to have to figure out if you actually do have an inverter or not. If you do, how big is it (how many watts) and what outlets does it supply? Also, how many batteries do you have providing power to the inverter.

If you included the year, make, and model of your motorhome in your signature, people might be able to tell you what's normally included in that unit.

An alternative is to get a 12V power supply for your CPAP, and connect it directly to the 12V power in your motorhome. What model CPAP do you use?

If you were plugging your "outlet adapter" into one of the 12V plugs in the dash, those might be on the chassis battery system and only activated when the engine is running. You could install one of those (female) plugs on a 12V line in the bedroom, and use the adapter there. You'll need to find a line that's always active (before a switch), make sure it's sized appropriately for the load, and install a fuse when you put in the plug. Depending on the location of your batteries, it might be easier to run a new wire directly from the batteries to a suitable location in the bedroom. Again, make sure it's the right size wire and appropriately fused.

wa8yxm · 11-05-2014, 09:12 AM

Two choices (Well 3 but "Don't Go" I assume is not an option)

1: Get a small inverter.. I really like true sine wave inverters because things you plug into them work, period, no questions.

2: Get a 12 volt CPAP machine (many already are check with the manufacturer of yours).

NOTE: Inverters are battery hogs, the bigger the faster they suck your batteries down. However for your machine you can get by with a fairly small inverter... (you can get TSW down to around 300 watt, MSW down to 100 or less) what is the wattage requirment of your CPAP.. if it's low enough you might be able to get by with one of these "multi-power station things (jump start, air compressor, work light and inverter in one box) most of them are in the 20-somethign amp hour AGM battery class and can thus deliver aroudn 100-150 watt hours before re-charge.. Mine takes like 3 days to charge though. I like 900 or more peak amp models (just in case I need to jump something) found smaller ones do not always have the cranking amps.

mel s · 11-05-2014, 09:28 AM

Quote:

Originally Posted by wa8yxm

Get a 12 volt CPAP machine (many already are check with the manufacturer of yours).

My CPAP runs on either 120VAC or 12VDC.
I the coach I usually run it on 12V, (even if/when I have shore power).
However we boondock often and I've never had a battery, or a CPAP, problem.
Mel
'96 Safari

nothermark · 11-05-2014, 09:28 AM

FWIW one of the folks I swap stories with needed a CPAP. They found it consumed one one storage battery per night. As I recall he got by adding a second battery to his unit. If you are in a smaller single battery unit that is an issue. Ditto if you are finding your 12V system needs a recharge in the morning no matter how many batteries you have.