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Small Cabin Forum / Off-Grid Living / Simple Solar. It’s easy- our setup.
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# Posted: 31 Aug 2021 10:12 - Edited by: Grizzlyman

Hi all. I just thought I’d share since there’s a lot of info about solar setups and it can be confusing.

Here’s a very simple setup that we have that works great for us for our off grid lake cabin.

Now this is a lake cabin- so we’re not running TVs and electric appliances. We use electricity for lighting and a few fans. For this- it’s perfect. Our cabin is very well
Lit and we don’t need to “scrimp and save” electricity.

Here’s the setup.

I bought two 100 watt panels on Amazon for $175. That came with a charge controller, wires, and mounting hardware.

The solar panels mounted on the roof run to the controller. The controller runs to a deep cycle 12v marine battery. The controller charges the battery and keeps From overcharging. It’s also nice in that it tells you % battery charge, voltage, and the output of the panels at any given moment.

The deep cycle battery runs to a “fuse panel”. The fuse panel runs to the various lights/ fan in 4 seperate circuits. Fuse panel is a safety measure to ensure amperage doesn’t exceed what is allowable.

That’s it. Easy. Basically the battery powers everything at night and the panels charge the battery during the day.

Everything is 12v. You can find RV fans that use 12 v, and you can find 12v lights- again usually for rvs.. We actually did a 3rd option and bought normal 110v sconces and fixtures, and just put special 12v led Edison base lights in them. We did this because selection is lacking for 12 v lights.

The biggest problem with 12v- and the reason it is not used widely is amperage and wire size. The Less volts the higher the amps. The Higher the amps the bigger the wire you need. The longer your wiring runs, the bigger the wire you need as well. If you put too much amperage through too small of wires- they heat up quickly and bad things happen. It doesn’t take long until you end up with huge thick wires to support 12v systems -which is why we use 110v in our homes.

An option for solar is to use an inverter which turns 12v into 110v- though 110v has its own set of problems- including codes/inspections. This is why I simply went 12v.

For wiring I bought a roll of 500 ft THNN stranded 10AWG. Why 10AWG? (That’s a good size wire) because of a need for bigger wire size again due to increased amperage.

That roll was $130 at Home Improvement store. That was sufficient to wire my entire cabin. This is probably less expensive- or at least the same as 14/2 romex for 110v.

You’ll want to use a few seperate wiring runs or circuits to keep the amperage down on each wire- again this is the #1 issue with 12v.

I have 4 circuits. These power as follows:

1. Total of 3 bulbs, 1 usb, and 1 light strip. wire length of 40ft.
-Led 12v light strip in the loft.
- 12v Edison base bulb light in kitchen in 110v ceiling fixture
- two hanging 110v light fixtures with 12v Edison light bulb in dining room.
-USB charger.

2. Total of 4 light bulbs and 1 usb charger. wire length of 30 ft.

-two 110v sconces in living room with 12v Edison lights.
-two 110 v sconces in bedroom with 12v Edison lights.
-USB charger.
-We also run a small usb ceiling fan off this usb charger

3. Big 12v RV ceiling fan. Wire length of 25ft.

4. Porch - hanging 12v light string. 24’ long string. Wire length of 15 ft. This is separate only for convienience of location- no amperage concerns with just this string.

Thats it it and is more than sufficient to meet demands and light the cabin very well.

Our wall sconces have switches on them- so no need for additional switches. I did install 12v wall switches for the kitchen, dining hanging lights, and porch lights.

The rv fan has its own switch.

Anyways- this is lengthy but I hope it helps some of you trying to decode all that is electrical

Disclaimer im not an electrician but come from
A family with several- so I know more than most on the subject.

Edit *** Also- I know it may not be “kosher” to use 110v fixtures with 12v bulbs- but I fail to see the problem- as a fixture is just wires and a connection surrounded by ornamentation. I’m not sure why those wires and connection are any different than any other aside from increased amperage due to 12v- but if they are appropriately sized which they are then I see no concern.

# Posted: 31 Aug 2021 13:59

If there is no 120 VAC wiring along with the 12 VDC wiring then there is no down-the-road safety thing. It can get dangerous when there are both 120 VAC and a lower voltage DC using wiring that appears to be the same. That is with looking to the future when someone who has limited knowledge about electricity and no knowledge of the system in place in your cabin may be asked to do something.

# Posted: 31 Aug 2021 17:14 - Edited by: Grizzlyman

Quoting: ICC
That is with looking to the future when someone who has limited knowledge about electricity and no knowledge of the system in place in your cabin may be asked to do something.

We don’t have 110v

# Posted: 1 Sep 2021 08:32 - Edited by: gcrank1

Looks like a good, functional 12vdc system
We had much the same for a fair long while, then we found having some light-duty 120vac would be nice so I wired in a 300w pure sine wave inverter and used a basic 'power strip' as its circuit. Inexpensive, easy and did the job nicely. NO permit, inspection, etc. required.
For running tools, microwave, toaster, old 30 cup coffee perc as a water heater we run the quiet little 2000w inv/gen (which also has a battery charger to the bat-bank whenever it runs; ie, might as well keep amps pumping into the bats whenever possible).
Btw, the gen isnt run much but sure is nice.

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