Inverter - Inverter/Charger

You need to read and understand how inverters do the job for you, and the amount of battery power needed to power things like microwaves and air conditioners.

If you read "The Twelve Volt side of life" Part II it explains all about it.

Inverters

Inverter/charger combos - way to expensive and require hardwiring into the camper's electrical system and the removal of your current charger/converter.
On the flip side, you also need to understand there are also 2 kinds of inverters -- true sinewave and modified sinewave, true being more expensive than modified.
Without getting too technical, the difference is--
True sinewave - as close as you can get to true household 110v. Puts out a nice clean 60hz (cycle) sinewave, but cost more.
Modified - Puts out a harsh 60hz square-wave. Much cheaper, but not good for sensitive electronics, and especially medical equipment.

I would look into Xantrex True Sinewave inverters. They're about as clean as you can get for a reasonable price.

Keep in mind, depending on what you're running off them, inverters draw a LOT of amperage from your batteries. I run 6 golf cart batteries, and that gets me easily 3-4 days of running anything I want before I need to consider recharging. But again, that's SIX batteries.

Your CPAP may well run on 12V particularly if it uses a wall wart at home. It is more efficient not to have to use an inverter and many of them now have a battery available.
Some appliances work fine with a modified sine-wave inverter (they are less expensive) others are not happy with anything less than a true sine-wave. I chose a Morningstar SureSine 300W, very efficient no moving parts... enough for your CPAP not enough for a microwave.

CPAP & tv are easy. 300w would serve you fine. I recommend two batteries but one might get you by. I am sure your CPAP will recommend sine wave or no inverter.

Microwave needs 1800+ watts of sine wave inverter and should have minimum four batteries to drive it. This gets a bit more complex and expensive.

I would try to do without the microwave or get a small Honda 2000 to run the micro and charge batteries.

If you really want to avoid the generator you are probably also looking at solar to recharge batteries.

It is your call. If you are inclined to do the project you will get lots of help and advice. Need lots of planning to see what will work best for you.

You need an inverter, not an inverter/charger.

A simple 400 watt MSW inverter should run most televisions and entertainment equipment.

You will need a larger inverter and lots of batteries and then a generator or solar for recharging if you want to use heavy loads like a microwave.

You can get a 12v adapter to operate a Resmed CPAP for $85 and for a Respironics it costs about $30. Many CPAPs can run straight from 12vdc with an adapter and is more efficient than using an inverter.

I suggest you sit back, get comfortable and use the search engine of this website. Everything you want to do is possible but you need to educate yourself on how all these things operate.

First you do not need an inverter, You need a new CPAP one that runs on 12 volts.

Second, you can indeed buy an inverter, I am very surprised that the dealer did not show you some on his shelf, Camping world has 'em, Most better RV dealers have 'em. Wal*mart has 'em but I'm not recommending those.

What I do recommend is a True Sine Wave inverter... here is why:

Though I no longer find it back when I got my Xantrex Prosine 2.0 they had a document on their web page for a no longer made MSW inverter with a title something like. "Things that may not work properly on a MSW inverter"

It was a long list.. and they forgot one item "Any item needing more power than the inverter can deliver"

Some entries: Any device with a digital clock or timer (Coffee pots, microwaves, Clocks) Radios, televisions, sat receivers (need not be connected to the inverter for it to cause interference) ELECTRIC BLANKETS (Believe it or not) and LED night lights. And a lot of other things.

The list for my Prosine (True Sine wave) is... Any item needing more power than the inverter can deliver.

That is the whole list.

For this reason I recommend a True Sine Wave inverter.

One more thing... Mounting the inverter

Mount the inverter as close to the batteries as you can but NOT in the same air space (Compartment) make sure battery fumes do not get to the inverter (They do not mix well with electronics) and run 120 volt wireing to the bedroom. Put an outlet next to the bed which is different from the rest of the outlets in the rig (unless you use a transfer switch) IE: if they are white, cream or off-white, use a black or better yet red or orange outlet (Red/Orange, Emergency colors for Emergency power).

as was said, you can get a 12v CPAP and not need an inverter.

and you can also run your CPAP on an inverter, along with running a tv.

BUT running a microwave on an inverter is a totally different deal.
this would require a bank of batteries and a much more expensive inverter.

i agree about getting an inverter and using a small quiet inverter generator for the microwave and for recharging your battery.
i installed a 400w inverter for the tv/dvd and to plug in electronic devices.
and we have a Honda 2000 to run the microwave and recharge the trailer batteries.

Suggestions to run the small Honda gen for bigger things and just get a small inverter make sense unless you have generator hours at your park that don't work for when you want to use the big things.

eg, BC provincial parks allow gens between 9-11am and 6-8pm. So if you want real toast (instead of that lame and nasty bread-burner rack for the propane stove) for breakfast at 7am, now what? That's where the bigger inverter comes in so you can run your toaster for three minutes drawing 90amps from your battery bank.

In winter it is dark by 6pm too, so who wants to go outside in the dark and play generator? In the rain. What if you want to make supper at 5pm and want to use the microwave? This is what the inverter is good for.

You just run the gen at a more convenient, allowed time to recharge the batteries. The big inverter means you are free to do what you want when you want. Of course it is necessary to rig your RV so you can do that, which may or may not be 'worth it' depending on how you like to RV.

They make generators you do not have to go outside for And please get an Inverter generator if you plan on running it after hours.

(Yes they are expensive... but worth it).


One figure you may need to know.. A pair of GC-2 (six volt golf care batteries, wired in series to give 12 volt) gives you about 1KWH of usable power at the overnight rate. You will loose about 10% if you convert it to 120vac using an inverter.

So you may want more battery.