Log In | Register
Skip to main content
Topic: 12v system (Read 285 times) previous topic - next topic
0 Members and 3 Guests are viewing this topic.
12v system
I'm trying to better understand the 12v circuit in my 02 RK.  There is a 700w inverter located below a drawer (at floor level) where the water pump is situated.  It appears this is wired to the over an entertainment center, where outlets are for the Tv and Dvr, etc.  The outlets in the coach, located at the bottom of overhead cabinets, appear to run 120v only.  Does this sound standard?  I'd like to be able to plug in a computer at the rear dinette and run off the 12v system, rather than having to run the generator or connect to shore.  Any guidance would be appreciated.  Matt

Re: 12v system
Reply #1
I have a similar configuration in my 99 IB. We decided to just use an extension cord plugged in at the outlet for the TV. I do not know if my stock  inverter is a modified sine wave or pure sinewave. For a permanent solution it is recommended to install a pure sine wave Inverter for sensitive electronics and hardwire a separate outlet. You can also refer to Terry Tanner's posts on Technsnoz  on this subject.
1999 26.5 Island Bed

Re: 12v system
Reply #2
The inverter setup described is standard for those rigs with an entertainment center.

>I'd like to be able to plug in a computer at the rear dinette and run off the 12v system.
Fine, if your computer uses 12volts, but few use exactly 12, usually some "odd" number like 18 or 22 or?
Maybe you meant adding another inverter? That MAY work. The factory 12volt wiring can handle up to 10amps, but that drops as the distance from the power distribution box/battery increases. Hence my qualification of up to 10amps. So see what your computer uses and if it's less than 10amps, you can give it whirl.

The wiring raceways are in the bottom of the bins. You remove the 50 staples holding the covering down and you will find both 120v and 12v wiring there. You then have a choice of hardwiring a inverter or adding a 12v outlet. If the latter, may as well add two. The second will prove useful for something. Maybe for plugging in a USB charging thingie. Can't have too many of those.

Perhaps the way I ran the inverter output on our MB could be adapted to your floorpan?
 
Don & Dorothy
Sold our LD in June of 2023

Our boring always non-PC travel blog
Traveling Dorothy

Re: 12v system
Reply #3
In cases where Lazy Daze installed an inverter, it was wired only to a duplex 120 VAC outlet near the entertainment center, and was intended to power TV/VCD/DVR/satellite receiver type devices that were not available in 12 VDC versions. These factory-installed inverters were hardwired to the house batteries and remotely controlled by a rocker switch placed near the inverter-powered AC outlet. They were not wired to the rest of the coach's AC outlets, which are entirely independent.

"I'd like to be able to plug in a computer at the rear dinette and run off the 12v system, rather than having to run the generator or connect to shore."

To use the factory-installed inverter, you'd need to run an extension cord to its outlet. If that outlet is in an overcab entertainment center and you want to be able to use your computer in the extreme rear of the coach, that could be awkward.  A better alternative would be to buy a 12 VDC power adapter for your computer and use a 12 V outlet near the dinette table. Failing that, you could use a small plug-in inverter and your laptop's AC power brick.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"

Re: 12v system
Reply #4
Helpful - thanks.  My setup appears to be a Andy describes it, to duplex outlet inside the entertainment center cabinetry that is connected to the factory invertor.  Perhaps running an extension cord may be the simplest solution right now.  There is almost continuos cabinetry from the front outlet to the back dinette to conceal the cable run.

Re: 12v system
Reply #5
"Perhaps running an extension cord may be the simplest solution right now."

But bear in mind that in the long run, a DC-to-DC adapter for your computer will be more power-efficient than using an inverter to convert 12 VDC to 120 VAC, and then using your laptop's power brick to convert 120 VAC back to 16-18 VDC.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"

Re: 12v system
Reply #6
My computer is a all-on-one desktop that I use for photography art, so it doesn't have a battery option unfortunately.  Matt

Re: 12v system
Reply #7
Overlander, I can sympathize.  I use a iMac and a out of date photo program to process my photos (Nikon NX2).  I am going to have to replace the iMac some day with a laptop.  And have to move on to a new program to process photos from my camera.  I never liked the Corel Software.  Maybe I should try it again it has been several years.  But NX2 was so much easier to use for what I do as compared to CS3.
John
07MB
Currently: 2008 36' Tiffin Open Road
Previously: 2007 Mid Bath

Re: 12v system
Reply #8
Don't get me wrong, I love the screen size and speed of the desktop.  Obviously, it's more cumbersome than a laptop, especially in an RV, and has the power consumption drawback, but it's big part of my enjoyment in life so I'm okay with that.  I'm working on figuring out the most comfortable workstation in the LD.  Matt

Re: 12v system
Reply #9
I understand.  I often will look for a campground with power to do laundry and photo processing when on a trip.  Note on the east coast that mostly lets out national parks and campgrounds (where a lot of good pics are).
Currently: 2008 36' Tiffin Open Road
Previously: 2007 Mid Bath

Re: 12v system
Reply #10
Running a desktop, along a decent size monitor, is going to use a lot of power, if it is used much daily.
Do you have adequate solar to keep up with the power demands? Are more batteries in your LD's future plans?
Small inverters have a bad habit of dying at the least opportune time, consider carrying an extra inverter and have the tools needed to exchange it.
Many of our  electronic's power supply's do not care if the power source is pure-sine wave or modified-sine wave.
Modified-sine wave inverters are a lot cheaper and more readily available. See if you can find out what is acceptable
to your computer's power supply..

Most of us have reduced our power usage by using tablets and/or solid-state memory laptops,
something to consider for the times you don't need the extra computing power or the resolution of the monitor.
This, and conversion to LEDs, is a way of significantly reducing the power demands.
Switching to a iPad and MacBook significantly reduced our power usage, compared to the old school laptops.
The tablet uses a 5-volt, USB charger. The solid-state laptop sometimes goes for days without recharging.
Using the same operating system, for all devices, helps keep things in sync.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

Re: 12v system
Reply #11

"I love the screen size and speed of the desktop. Obviously, it's more cumbersome than a laptop, especially in an RV, and has the power consumption drawback, but it's big part of my enjoyment in life..."

I understand, Matt, because my usage is similar to yours. But I've learned that it's possible to have your cake and eat it too. :-) Read on...

My computer has always been used heavily for photo processing and graphic design. In my first ten years of full-time RVing I used desktop iMacs, starting with a 20" model in 2005 and working up to a 27-incher. I don't have to tell you that a large screen is tremendously useful for that kind of work, especially when combined with a Wacom tablet. Early on I tried using a 17" laptop, but the screen just wasn't big enough--and worse, the color and contrast changed every time I moved my head or tilted the screen, making serious photo work impossible. I went back to the big iMacs.

But as Larry noted, big screens use big power. One of the main reasons I've ended up with 600 watts of solar panels and 500 amp-hours of batteries is that I had to have them to support my computer use. My need for a big screen cost me several thousands of dollars in upgrades.

Meanwhile, Jan Forseth and James Hager--two friends of mine who are professional wildlife photographers and travel full-time--had gone a different route. They use 15" MacBook Pro laptops for routine tasks such as emailing and web surfing, but connect the laptops to 27" Apple Thunderbolt displays when processing photos. This lets them get away with minimal power usage most of the time, and only turn on the power-hungry big screen when it's really needed.

About a year ago I decided to try a similar approach. I replaced my 27" iMac with a 13.3" MacBook Pro plus a 27" Apple Thunderbolt display. Like my friends, I use the laptop most of the time, but plug in the big screen when I need it. (I use an ArcBook stand to hold the MacBook in "clamshell mode," and use a standard USB keyboard and mouse.)

My power usage has gone down considerably with this setup. After decades of large-screen use, I was skeptical about using a small laptop screen for most of my work (such as this post), but I was surprised at how quickly I got used to it. When I need a big screen, the 27" Thunderbolt display supplies power to the MacBook, and also acts as a USB and Thunderbolt dock, so I leave my full-sized keyboard, scanner, printer and other peripherals plugged into the big monitor.

You get the idea: I use the laptop much of the time, minimizing drain on my batteries, but when I need the big screen, I switch on the inverter and I’m in business. As a bonus, I can carry the MacBook into the kitchen and use it at the dinette, or in the rear lounge while sitting at my Lagun table, or take it to a Starbucks and use their Wi-Fi to download software updates. I couldn't do that with my iMacs!

Something like this might work for you. Just a thought...

As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"

Re: 12v system
Reply #12
As a postscript, I've recently started using my iPad Air as a small second screen for my MacBook Pro. The Duet utility makes this possible, with nothing more than a USB cable connecting the two. Now, you may have seen ads for USB-connected auxiliary video monitors. They're available for as little as a hundred bucks. But the Duet/iPad setup is a whole different ballgame. When you think about it, it's a safe bet that any recent iPad has a far better (Retina) display than some no-name hundred-dollar screen from Walmart.

I set up the iPad alongside my MacBook Pro, plug in a USB cable and launch the Duet app on the iPad. It connects to the MacBook (which is running a free Duet utility in the background) and bingo! my Mac desktop is now twice as wide. I can drag windows from one screen to the other. There's no noticeable lag or flicker even when playing videos, and the iPad's 2,048 x 1,536 Retina screen is just as sharp and bright as the 2,560 x 1,600 Retina screen on my MacBook--which is to say, very good indeed. :-)

In short, using an iPad as a second screen makes a laptop easier to live with, and the iPad's power consumption is minimal. Of course I still resort to the 27" Apple Thunderbolt display when doing serious photo work, but I'm finding the iPad a nice step up from just the laptop screen.

The Duet iOS app costs twenty bucks--a lot cheaper than buying a second monitor. And by the way, Duet is available for Windows as well as macOS, so if you have an iPad and a PC, you could do the same trick I just described.)
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"

Re: 12v system
Reply #13

About a year ago I decided to try a similar approach. I replaced my 27" iMac with a 13.3" MacBook Pro plus a 27" Apple Thunderbolt display.
Like my friends, I use the laptop most of the time, but plug in the big screen when I need it.
.......My power usage has gone down considerably with this setup. /quote]

Besides saving a lot of battery power, MacBook Pro's retina display is very easy to look at.
With the hotspot, we can sit outside and use the laptop or tablets.
The laptop's screen can be displayed on the TV, through a cable or an Apple TV device.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze