No outlets work on battery

Boondocking this past weekend, I discovered that none of the outlets work when operating in battery mode. Does the cigarette lighter outlet work off of battery? The issue still plague-ing me is the CPAP machine my husband uses. Can I buy an inverter with a regular outlet on it and a cigarette lighter insert to use on the cigarette lighter outlet? Would that work?

[Bill]

Judy -

The outlets are not intended to work when your only power source is battery (DC) power. The outlets provide AC power (house power), and work when you have shore power or a generator.

Yes, the cigarette lighter outlets work on battery, and you can plug in a small inverter to power an AC device such as a CPAP machine. Of course that means it is quite possible to drain the battery into whatever you plug in, so be careful.

Several years ago we had some long discussions about CPAP machines, and how to power them while boondocking. You would do well to Search for those discussions - there were several, and they had a lot of good content.

If you decide to use the cigarette lighter for power, there is one hint that may be helpful. The cigarette lighter outlets in the Winegard TV plates are very tight, and it is possible to break them when repeatedly inserting/removing a plug. You should probably go to Radio Shack (Catalog # 270-043 or 270-050), Camping World (Item #29011), an RV store, WalMart, whatever is handy, and buy a multi-port extension to plug into the outlet. It is like an extension cord - it has a plug that you plug into the existing outlet, with two or three extension outlets. You plug it in and leave it forever, and plug you CPAP or other device into one of the extension outlets.

Bill

Thanks Bill. Checking with CPAP manufacturer to see what it's requirements are. They show an inverter that's 300w output (pure sine wave) for his model. Think I'll get one with a little more wattage for safe measure.

I'll definitely get the "permanent" outlet to extend the wall receptacle life. Great suggestion!

I would seriously consider adding a second deep cycle battery if you plan to boondock with a CPAP. They will run down a single battery pretty quickly. The inverter is not 100% efficient which adds to the load. You want to have enough battery capacity to not run them to less than 50% of capacity or you will significantly shorten their life. And you will need to have at least a small genny to recharge them.

Remember that a device using one amp at 120v is using 10a or more at 12v, assuming inverter losses. The amps add up quickly.

I am on my second CPAP now and the first one came with the 12 volt plug-in. It had very little draw and I could get by two nights on a jump-start power pack. I also ran it on a 75W plug-in inverter in my van. During our last ice storm a couple of years ago I gave the 75W inverter to my son and used a 200W attached to my car battery. When the battery had dropped to 75% it shut off to prevent the car battery from running down so far that it would fail to start the next morning. But it left me gasping for air and I had to try to sleep sitting up the rest of the night.

Bottom line, don't buy an inverter for the CPAP that is any larger than necessary. A CPAP plugged into a 1000W inverter will run down the battery down faster than one plugged into a 100W and it won't run any better.

Thanks for all of your input! We weren't entirely boondocking for the weekend. We had the generator hooked up and running when something (low oil) knocked it out in the middle of the night. Not knowing at the time about the oil issue, I thought we could just run his CPAP until morning off the battery. NEWBIE that I am, that theory was flawed. Now, I'll get the inverter and have talked with my electrician about a 2nd battery. With the Trailmini, the area under the lounge is pretty tight, but we think we can get that 2nd battery wired in series under the couch.

It's always something new that gets me in trouble, but I keep reading all your advice and am learning slowly but surely .

[Bill]

... we think we can get that 2nd battery wired in series under the couch

Judy -

Be sure you know the difference between wiring a new battery in series vs. in parallel with the existing battery. Things will get really exciting, really fast, if you do it wrong. A Search here in the Electrical Forum will turn up helpful posts, including pictures.

Bill

You're right Bill. He's a really great licensed electrician. I'm not very good at the terminology, but Greg knows his stuff, so I'll trust him to do it right.