Simple Electrical for Off Grid Question

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Small Cabin Forum / Off-Grid Living / Simple Electrical for Off Grid Question


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TiffanyKruzer Member	# Posted: 21 Apr 2024 15:10 Reply Hello, I'm in the process of solo building a simple 16x20 off grid cabin in the middle of a forest in Northern MN. It has been a rewarding process! Last summer I got it dried in, so really just focusing on the interior now. So far for power I've been using an EcoFlow Delta Max (2016wh) and I've been charging it using a few small solar panels or a generator. That has worked fine and 2016wh fits my needs. So now I am wiring the interior, which is essentially going to be 3 or 4 outlets and a couple lights. This is a "weekend" cabin so I do not plan on any huge appliances, we are talking a small TV, charging phones, some lighting, maybe a small fan, etc. Here is where my question comes in... what is the simplest way to have my little EcoFlow "power" my 3 outlets and couple lights? Do I really just rig up the Romex into "plugs" that can be plugged into the EcoFlow? Do I need to wire up a small service panel and then figure out how to have the Ecoflow power the service panel? Is there an even better idea without going overkill? This small cabin will NEVER have grid power and is honestly just a weekend cabin. I even considered not doing ANY romex wiring and instead just run extenstion cords where needed from the Ecoflow, however that is not nearly as "clean". Thanks again for any and all input and advice! I'm a long time reader and this is my first post! -Tiff

travellerw Member	# Posted: 21 Apr 2024 16:04 Reply If it was me (and it was a few year back), I would follow code as close as I could. Code exists for a reason and you will never go wrong (or dangerous) if you stick to it. So romex back to a small service panel (with a main breaker) Then feed the service panel from the Ecoflow. You could also get fancy and rig it with a generator switch such that the cabin is powered from generator when its running. But powered from the Ecoflow when generator is off. Put an outlet near the ecoflow that you can plug it into, then when the generator is started simply plug it in. The key with 2 power inputs is they must NEVER be able to put power into the system at the same time (thus the generator switch). A setup like that will give you the option of using high power devices (like coffee maker and toaster). Fire the generator up in the morning to make breakfast and put charge into the Ecoflow, then run the rest of the day in silence on battery.

ICC Member	# Posted: 21 Apr 2024 16:37 - Edited by: ICC Reply ....pretty much what travellerw said. The biggest challenge is how to make it simple and foolproof to allow the generator or the EcoFlow to be the sole provider of power with no chance of somebody else messing something up and at the very least frying the EcoFlow or the generator. A generator transfer switch is one method. However.... Is the EcoFlow weather resistant or waterproof? If so the easiest method may be to locate the generator and Ecoflow both outdoors. Then wire the cabin infeed using a single weatherproof male receptacle as the inlet power port. One like this... https://www.amazon.com/Leviton-5278-CWP-Straight-Flanged-Receptacle/dp/B003ATXIBG?th= 1 With that on the outside of the wall, you would use a regular extension cord between the inlet power receptacle and the generator or the EcoFlow. No chance of connecting both at the same time. A simple 2 breaker service box is all you would need for the inlet power to connect to. Power to your few power outlets and/or an LED light fixture would be wired with Romex from there. There are indoor-rated and outdoor-rated boxes to choose from. With such a basic system I don't really think you would require a main breaker. The generator and the EcoFlow likely have a breaker built in to protect the units themselves. However, that would not hurt to implement.

gcrank1 Member	# Posted: 21 Apr 2024 16:55 - Edited by: gcrank1 Reply My old system was about as simple as it gets. The cabin input was an RV type plug outside for the gen to plug into. Inside from that was a single outlet. With the gen running that was plug and play with an extension cord....which morphed quickly into a typical multi-tap 'powerstrip' (with an internal circuit breaker). I ended up using one outlet of that dedicated to a small gauge lamp-cord upward to run the couple of standard light fixtures (Use LED bulbs!). There were no in the wall wires and easy to use while I worked out a plan for the future. To use the LFP bat/inverter (the basic equiv of your Ecoflow) I was the transfer switch; Id unplug from the gen feed outlet and into the inverter. NO chance of back feeding and blowing gen or inverter. This worked well for about 3yrs and would still but we are putting in a new cabin. It will be as mentioned, outlets every x feet to code, Romex in walls, small 2 circuit 'service panel' with cut-off throw. The RV input for gen will be the same but inside it will go to my new inverter c/w an internal transfer switch. The inv will also be hooked to the LFP bank and the service panel feed comes from it. Our use will be seamless other than charging the bats or starting the gen.

TiffanyKruzer Member	# Posted: 21 Apr 2024 22:24 Reply Thanks for all the suggestions so far! If I don't want to overcomplicate it by making multiple options for the Ecoflow and the Generator with transfer switch etc, then is the best way, assuming I'm only going to use the Ecoflow (which I could charge from a generator separately), is to get a small breaker box and wire the Romex into it and then figure out how to connect the "service" to that box via a cord to one of the AC plug ins on the Ecoflow?

gcrank1 Member	# Posted: 22 Apr 2024 08:26 - Edited by: gcrank1 Reply That is pretty much it. One pigtail c/w plug to use on either the gen or Ecoflow, never both at once. The box will be powered up fine because either does the same input to the box as a grid connection. The house type service panels are too big, expensive and have way too many circuit breaker ports. Look for an accessory box like one would use for a hot tub or pool as an add-on to a system. You wont need more than 15a circuits, imo.

Brettny Member	# Posted: 22 Apr 2024 12:42 Reply I would also do a breaker box. The small ones are very cheap and so is a 250' roll of 14/2 romex. I bet you could do the whole cabin and use up all that 250' for less than $200 with outlets, boxes and covers.

Grizzlyman Member	# Posted: 22 Apr 2024 18:00 Reply You could run extension cords or some other type of setup that is less than ideal- but really pulling wire through studs and wiring outlets in a box is not too difficult and 100% worth it to make it a little nicer. You could do the entire cabin in just a few hours if even that. My $.02

MikefromMichigan Member	# Posted: 25 Apr 2024 08:12 Reply I personally would skip the outlets. Just set it up so the batteries and entire electrical system is in one spot, preferably by the kitchen/living area . Put in a marine fuse box there to power all your DC stuff, which should be everything possible like lights, frig, fan, radio.... DC stuff can plug in right there to. That is the simplest, most efficient way to set it up and how I did mine. Keep in mind that mice will likely invade your place and they like to chew on wires. I like to have all DC wires visible so I can inspect them for mouse damage. I used to have wires running inside my walls and ceiling, but not any more for that reason.

Brettny Member	# Posted: 25 Apr 2024 09:31 Reply I have found that DC lighting is very limited, very expensive or doesn't work properly. So much so that in my new cabin I have changed all my lighting from DC to 120vac. It's time tested and I can go to any store and find a fixture, light, switch and outlet. 120v stuff is actualy just cheaper to buy also. As to DC fridges and fans. They also cost more to buy. Where as just running standard AC stuff costs less meaning you have more money for a bigger solar/battery.

gcrank1 Member	# Posted: 25 Apr 2024 09:48 Reply With our new prebuilt log cabin I don't have any wiring installed but for the 2 ceiling 'drops' to install fans c/w lights, the channels are milled & drilled in the logs though. It will take me a while to run the stuff.....and the new inverter, etc. that I prev mentioned. So my plan is to initially use the usb rechargeable and easily moved lights Ive accumulated the past couple years (as well as my old bat 'camping lanterns). For us, out of the 5 lights we had in the old shack, 1 got the most use, another a bit and the rest rarely. If/when we want the tv/vcr I can run a cord off the power-base. All that will be better than the old kero lamps we used to use!

travellerw Member	# Posted: 25 Apr 2024 10:03 Reply Quoting: MikefromMichigan That is the simplest, most efficient way to set it up and how I did mine. While that is true.. The %4 loss through a quality inverter is worth it for cheaper appliances and lights. Not to mention I'm not a big fan of having batteries in the living area. Especially FLA that off gas like mad when cycling.

Tim_Ohio Member	# Posted: 25 Apr 2024 11:21 - Edited by: Tim_Ohio Reply I do this, but just plug the generator into the outside service entrance outlet (twist lock) when running on generator. At night, I unplug the generator and plug in the 12 volt battery using a cheap inverter. This way, I just need power to flip a light on for whatever reason and to charge my cell phone overnight. The cabin is set up with a service panel just like a house, except, as mentioned above, a generator box with a male receptacle is mounted outside on the wall of the cabin. I like to take home the expensive generator and not risk it being stolen. There was nothing special about it since the system is not unlike a house. Everything is grounded with two rods and even a wire running off the rods is left to connect to the generator (most of the time I forget). I run the generator in an insulated shed and can't even tell it's on. The shed is fitted with a fan and vents and is placed out of direct sunlight. The battery and inverter are kept in a plastic tub. I plug it in and slide it under the cabin (elevated) out of the weather. The cabin has metal enclosing the underside, so I don't fear any fire hazard. I think it's pretty safe. Technically, the generator should be started after you assure all loads are off. This means, it is plugged into the cabin first. The breaker is off to the cabin. The generator is fired up, then the main breaker can be flipped on. Powering down is the reverse. Unplugging the generator is after is has been turned off. Plugging the inverter and battery in is the same. All loads off, then plug it in and close the breaker main to power up, safety first. I hope some of this information will give you some ideas.

MikefromMichigan Member	# Posted: 25 Apr 2024 11:29 Reply I have run DC lighting in my cabin for 30 years starting out with incandescent bulbs and now running LED bulbs for the past 10+ years. The LED bulbs are a little more expensive, but not much more. They last a very long time. In fact, I'm still running most of the original ones I bought 10+ years ago. In my opinion, they work just as well as DC bulbs. They are easy to wire and I'm using standard lighting boxes and fixtures, so the cost of that is the same. You can use the same RGB wire for AC and DC, or you can use lighter, low voltage wires for DC. I use both. I have had a AC/DC frig for about 15 years running it solely on DC. Its super energy efficient and has been wonderful. For a cabin, it's ideal. I also have a DC stereo, fan and other stuff, none of which cost much, if any more than AC stuff. The only things I have to run an inverter on are my TV (don't used it much) and charging some items. I can get by with 200 watts of solar power and a 200 amp lithium battery. I have not had to run a generator my cabin since I got the new battery two years ago. I stay there pretty much all fall (mid-Sept. - end of Nov.) and I am in the U.P. so in Nov. the sun is low in the sky and days are short. I can easily take down my solar panels and store them inside when not used, which is important since bears would likely ruin them otherwise.

MikefromMichigan Member	# Posted: 25 Apr 2024 11:34 Reply Quoting: travellerw While that is true.. The %4 loss through a quality inverter is worth it for cheaper appliances and lights. Not to mention I'm not a big fan of having batteries in the living area. Especially FLA that off gas like mad when cycling. I have read where inverter loss rates can be a lot higher than 4% epically at high loads.

Brettny Member	# Posted: 25 Apr 2024 12:09 Reply I'm sure there are many higher than 4%. All depends on all of of factors. Here's a DC fridge story for you. I have family with a nearly new RV that has a 120v/12v/propane fridge. The fridge uses as much KW as my 120v standard double door fridge with ice maker. It does this because its propane so needs to make heat to keep things cold.

MikefromMichigan Member	# Posted: 25 Apr 2024 13:43 Reply Quoting: Brettny I'm sure there are many higher than 4%. All depends on all of of factors. Here's a DC fridge story for you. I have family with a nearly new RV that has a 120v/12v/propane fridge. The fridge uses as much KW as my 120v standard double door fridge with ice maker. It does this because its propane so needs to make heat to keep things cold. Not suprising. My DC frig has a compresser that uses 35 watts.

travellerw Member	# Posted: 25 Apr 2024 14:06 Reply Quoting: MikefromMichigan I have read where inverter loss rates can be a lot higher than 4% epically at high loads. Cheap inverters relying on inefficient designs for sure. However, quality ones that are closely matched to your loads (you don't want a 3000W inverter if you are only pulling 500W) are %94-96 efficient. I converted a stand-up freezer to a fridge that is run off our inverter. Its more efficient than ANY fridge I could find and was WAY WAY WAY cheaper. With conversion it was like $200 cdn and the conversion took me all of an hour. Tough to beat that. So nice to just go buy something 110V and not have to worry about a semi-custom 12V system.

Brettny Member	# Posted: 25 Apr 2024 17:36 Reply Quoting: MikefromMichigan My DC frig has a compresser that uses 35 watts. That really dosnt matter. KWH or WH matter in this use because a fridge cycles on/off.

MikefromMichigan Member	# Posted: 25 Apr 2024 18:19 Reply Quoting: Brettny That really dosnt matter. KWH or WH matter in this use because a fridge cycles on/off. Sure it matters. Electricity use varies with outside temperature and how much the door gets opened. When it's running, it is pulling 35 watts. It has 3" of insulation for the frig and 4" for the freezer. It normally only runs for 10 minutes every two hours at normal Temps. I have it in a cold room though, so it's usually less than that.

paulz Member	# Posted: 26 Apr 2024 10:28 - Edited by: paulz Reply Still 12v DC here for most everything daily: lights, water pump, TV, modem, fridge. Inverter normally off: microwave, tools, washer. If I had it to do over like gcrank would I rethink it? Probably, and yeah maybe it used a bit more juice. Moved the fridge outside this winter, no sense in heating that.