New trailer, now for solar

ApexAZ

Member
So we should be picking up our new Fuel Toyhauler on Saturday and we need to install a solar panel kit with inverter.

I have about a zillion questions regarding solar, but my most pressing question is in regards to AC inverter and DC converter.

I have to use a CPAP machine at night and my particular model doesn't seem to support AC Inverter supplied power. I plan to call them tomorrow to confirm and find out why, but based on their battery use instructions, they say a DC-to-DC converter is needed and AC Inverter is not recommended.

We also want to install a solar system with an AC inverter, which sounds like it may not be compatible with my sleep machine.

So my question is this: could I connect a single battery to both an AC Inverter and simultaneously run a 12v connection to an outlet in the bedroom to be used specifically for my CPAP, or will this cause issues having two different types of power coming off the same battery?

I'm sorry if this is better suited for the other electricity forums. I wasn't sure which to post to, since it involves both :)
 

Oregon_Camper

Well-known member
No problem running 12v to inverter and your CPAP. You can run a dedicated 12v line to bedroom or find an existing one. Depending on the amp draw you might have to pull larger (but the number are actually smaller for thicker wire) gauge wire.

Here is an example of my system, that could give you an idea of what do to

3160EL Power.JPG
 

Bogie

Well-known member
If your CPAP will operate on 12 volts, that's definitely the way you want to go.

All inverters draw a certain amount of current even in the idle state. Mine for example draws 4 amps at idle. So if you were operating with an inverter, you would be drawing the amount of current (Amps) need for the CPAP plus the overhead for the inverter. If you can connect your CPAP directly to the 12 volt supply, you will use less amp hours and draw your batteries down less while using the CPAP.
 

ApexAZ

Member
No problem running 12v to inverter and your CPAP. You can run a dedicated 12v line to bedroom or find an existing one. Depending on the amp draw you might have to pull larger (but the number are actually smaller for thicker wire) gauge wire.

Here is an example of my system, that could give you an idea of what do to

View attachment 66116
Excellent, thank you. Is that all Victron equipment? There doesn't really seem to be many dealers here in Phoenix. Is Renogy sufficient?
 

Oregon_Camper

Well-known member
Excellent, thank you. Is that all Victron equipment? There doesn't really seem to be many dealers here in Phoenix. Is Renogy sufficient?
I had a Renogy MPPT controller and replaced with Victron after 1 year. You can always find Victron products on Amazon.
 

ApexAZ

Member
I had a Renogy MPPT controller and replaced with Victron after 1 year. You can always find Victron products on Amazon.
Did you DIY all of it? It's a bit intimidating.

Also, why do you have the multiplus if you are running 2 separate controllers? I thought the controllers were for charging the batteries, so I'm not sure why that might be needed in the inverter?
 
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Oregon_Camper

Well-known member
Did you DIY all of it? It's a bit intimidating.

Also, why do you have the multiplus if you are running 2 separate controllers? I thought the controllers were for charging the batteries, so I'm not sure why that might be needed in the inverter?
Yep, I installed everything. The MultiPlus is a "converter" (creates 12v to RV and battery bank from AC) and "inverter" (create AC power from battery bank). The 2x MPPT controllers are only to power the battery bank from solar.
 

SLO

Well-known member
I run my cpap off my Magnum MS2812 inverter when dry camping. It supplies the same 120v power as when you’re plugged in. Just need to make sure your inverter is pure sine wave.


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ApexAZ

Member
I run my cpap off my Magnum MS2812 inverter when dry camping. It supplies the same 120v power as when you’re plugged in. Just need to make sure your inverter is pure sine wave.


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You know, it's interesting, because my in-law's had a 5th wheel with a pure sine inverter and I ran my cpap off of it with no problems. This was without realizing it wasn't recommended by Resmed. But after doing some research recently, for whatever reason, they do not recommend using it on an inverter with my specific machine, especially with the humidifier. Some of their models are listed as being compatible for inverter AC power, but mine is not. They have all sorts of warnings about causing damage or personal injury by doing so. I called them and she basically said it can damage the machine and possibly start a fire.

I guess to be safe, rather than sorry, I'll just get the DC converter cord and have them install a 12v plug in the bedroom. It's easy enough I suppose.
 

SLO

Well-known member
You know, it's interesting, because my in-law's had a 5th wheel with a pure sine inverter and I ran my cpap off of it with no problems. This was without realizing it wasn't recommended by Resmed. But after doing some research recently, for whatever reason, they do not recommend using it on an inverter with my specific machine, especially with the humidifier. Some of their models are listed as being compatible for inverter AC power, but mine is not. They have all sorts of warnings about causing damage or personal injury by doing so. I called them and she basically said it can damage the machine and possibly start a fire.

I guess to be safe, rather than sorry, I'll just get the DC converter cord and have them install a 12v plug in the bedroom. It's easy enough I suppose.

We’ll I’ll have to check on mine now. My understanding is pure sine wave inverter is the same as your home power. At home you have a converter to convert from AC to DC. If you use that same converter in your RV your still converting AC, through your inverter, to DC.


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ApexAZ

Member
We’ll I’ll have to check on mine now. My understanding is pure sine wave inverter is the same as your home power. At home you have a converter to convert from AC to DC. If you use that same converter in your RV your still converting AC, through your inverter, to DC.


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Yeah, I really don't get it and she wasn't super technical to be able to explain in detail why that is; only that it's not recommended. Perhaps they are worried about less reliable modified, or low power inverters or something? But then on the other hand, they specifically talk about how inverters need to be pure sine wave and at least 300w with peak of 500w for use in the models that support it. Like I said, I used mine on an inverter and it seemed fine.

Nonetheless, it's not a big deal having a 12v plug installed.

Not sure if you use Resmed, but the info is here:


The warning is on page 5.
 
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SLO

Well-known member
Yeah, I really don't get it and she wasn't super technical to be able to explain in detail why that is; only that it's not recommended. Perhaps they are worried about less reliable modified, or low power inverters or something? But then on the other hand, they specifically talk about how inverters need to be pure sine wave and at least 300w with peak of 500w for use in the models that support it. Like I said, I used mine on an inverter and it seemed fine.

Nonetheless, it's not a big deal having a 12v plug installed.

Not sure if you use Resmed, but the info is here:


The warning is on page 5.

So my Resmed, AirSense 10 AutoSet, is not listed as approved on the document you linked. On mine if I used 12v dc direct from the battery, I’d need a dc to dc converter because my Resmed needs 24v dc. I already have the ac to dc converter that came with the cpap. The Magnum has enough watts, 2800w. I’ve used it this way for several years, because I didn’t know about Resmeds restrictions. I’ll continue to use the ac to dc inverter as I have it set up. One note, I don’t use the humidifier which would draw more amps.


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