.....and I am thinking of a homemade generator/battery bank.

This will be a small 24'x24' structure, well insulated, heated with a wood stove in the colder months.

The only electric I plan on using is LED lighting, a small college dorm sized frige, small flat screen TV, coffee pot.......but a small 5000 btu AC unit will be installed as well.

I built a homemade generator in the past using a briggs 5hp engine, running a GM alternator, that charged a 12v deep cycle car battery, with a DC to AC inverter attached to the battery. It worked well for running lights and low drain stuff.

Here is what I have in mind: I have a twin cylinder Briggs 17hp engine that is in great shape. I was planning on using it to turn one, or possibly two alternators to charge a battery bank of 6 deep cycle batteries. A high quality 3500 watt DC to AC inverter would be attached to the battery bank to supply AC power to my stuff.

Does anyone have experience with a setup similar to this?

How can you have an "off the grid cabin" in Nauru?

I change that little flag often.........I am not there.

Must not sleep. Must warn others.

PM Aviator.  He's got a battery setup in his cabin.

The big thing you are going to spend money on is a set of GOOD sealed batteries and a charge controller.  The controller is necessary for battery life, but expensive.

The price of the charge controller will pale in comparison to that of the batteries, generally speaking, but everything depends on the peak wattage loads and the total energy draw per day. You'll also want a pure sine wave inverter designed for continuous duty. I have such a setup for my basement circuits, but on a solar setup.

OP, list all the possible loads you'll have hooked up, and then you can start to calculate your wattages from there. Once you do that, it's a pretty easy math problem to figure out the specs you need. You'll want to keep your batteries below a 20% draw for maximum life (e.g.: if you have a 1 kWh energy draw per day, you need a battery stack with 5 kWh of capacity to make them last, assuming you'll be using the generation source serially).

I would look into 24v lights and gas appliances if I were you

Or just get an AC generator to attach to your motor

Go with Rocketman's advice.  My post was more of a generic since I have no hands on experience with anything other than the basics.  But yeah, really good batteries are going to hurt.

We ran a decent solar system at our cabin.
100 watt panel, feeding a 12v system.

1000w inverter.  Ffl lights, fans.  Worked well.

Also had a decent generator to run an ac in the summer.

Txl

The A/C and fridge will make your plan very expensive (the a/c in particular)

For a fridge, try and find a 12v/propane/110 one out of a camper. You can run them on a bottle of propane for a LONG time. Plus if SHTF...it will still run off of 12v

A/C... There is a reason that campers run A/C off of 110 or generator... huge power draw. Try a swamp cooler instead.

The retired couple across the street hand built a beautiful 1,100sq ft cabin on 17 acres. It's 1,900' up in the Bluffs 45 mi. west of nooga and is their seasonal summer home. They had a large LP tank installed and use LP for really cool old timey lights, water heater, range/oven and have a Sunlight brand gas fridge. They have both 7KW and 2KW Honda genny's to run the washer and gas dryer on wash day as well as any power tools. They have city water so a well/pump is not needed and a wood stove for heat. They have two mid sized PV panels charging 4 Group 31 AGM batteries they use for a 19" flatscreen TV, charging laptop-phones and running a surprisingly good sounding car AM/FM CD car stereo/bookshelf speakers.

Because they use gas for their primary energy they didn't have to spend a small fortune on large PV/battery system but they do have gas and water bills.

It's a very nice little hybrid setup.

My place is totally off the grid. We have 450 Watts of solar panels charging a bank of NiFe batteries that have an estimated life of 25 years. Our fridge, stove/oven, water heater and lighting is propane. Heat is from a woodstove. Run a Honda inverter gen for whenever we need AC and to run the washer. Water is from an old 25' deep hand dug well that is pumped up the mountain to a 1000 gallon holding tank which pressurizes the house system. I have both a 12v pump and a 120v pump to get the water up to the tanks (the 12v pump is slower, so usually I run the generator to fill the tanks). A thousand gallons of water will last us a nearly a month. Clothes are dried on the line and we have an outhouse for a bathroom. We have a dozen 100 lb. propane tanks that we rotate out (two hooked up at a time) throughout the year. We get about 30 days use per tank.

Here is a great form with a ton of information. The folks are very helpful and there are some electronic genius is on there that are really really helpful.

http://forum.solar-electric.com/forum

If you are looking to make a very fuel efficient generator look at a weed eater engine with a car alternator.

This sounds like a great setup

Figure out overall power needs.



Most folks use a small generator to run the ac unit.  Something like the harbor freight 2 cycle generator can be made to run one if you do it right, 100 bucks for that generator maybe?  The ac units that let you first turn on the fan and then kick the compressor on are generally easier to run with tiny generators since it is 2 smaller loads kicking in seperatly instead of combined at once.



Dorm fridge can be soso on efficiency, I have one and use it because I have it.  No I am not off grid.  I do have a chest freezer set up as a fridge though, lots of off grid folks do this because the chest freezer has better insulation and opening the top does not let all the cold air out.  Run a search on kegerator sites to read up on these, they do pop up on solar sites now and then.



Anything you can do 12 volt saves the power loss the invertor will have converting 12 volt to 120 volt.  A 20lb propane tank will make a lot of coffee, have you considered propane instead of electric coffee pot?  



I would run some searches on what your 17 hp engine might have for power output with a generator head vs some alternators.  I expect gas consumption to be higher for the power gained with the alternator setup.

You could pair this generator head with your 17HP B&S and get 10kW for only $299.

Thanks everyone for the information.....lots of good replies.

I will be calculating load, and go from there using suggestions here.

You need to make a false floor, that gives you outside access (preferably partially underground), with sides that are capable of stopping a large caliber rifle round. Why anyone would make a SHTF cabin that is off-the-grid without an emergency exit, and fortified hunker down area is beyond me. Things to think about pre-construction.

 

Don't know how this would work, but what about setting up the A/C unit to run directly off a small gas engine (eliminating the electric motor)?

Might try looking at Lehman's Hardware, too:

https://www.lehmans.com/

Lots of good off-grid ideas. But not cheap.

Interesting topic OP, I look forward to seeing how you progress. I would also consider a swamp cooler instead of an A/C unit. If the place is small an heavily insulated enough you could probably also just use a very small A/C very briefly to establish a low temp that was maintained throughout the day.



First off, that's very impressive. I have to imagine that took a lot of work and ingenuity to get up and running. Kudos for that. If I may ask though, what led to adopting such an extreme lifestyle? I am specifically thinking here of the outhouse. Even one deployment worth of using a porta-shitter made me incredibly thankful for indoor plumbing, and I have a hard time imagining giving it up voluntarily without a really strong reason.

Necessity I suppose. The home is a log home built out of American Chestnut and was constructed in the late 1700's, along with the well. The house and the surrounding 100 acres is what was left to me by my Grandparents. This place is quiet isolated and would take a bundle of money to get a line of poles from the power company up to it. The house was in disrepair when I got it and hadn't been lived in for a long time, it was pretty much an empty shell with a roof before I restored it. I have thought about putting in a septic, but the outhouse hasn't been so much of an inconvenience that I have taken that step, even when we have had temperatures well below zero its not so bad using it. Throw down a sprinkling of powdered lime after each use and there is not smell from it either.  We also have an antique chamber pot chair we use for pissing, which we empty out each morning. There is no city water available anywhere on that mountain, so a gravity tank was the best option to get water into the house. (The place never had indoor plumbing at all until I installed it). Several generations of kids were raised in the house way back when and living must have been much more primitive than what I have now (My wife and I have a five year old boy and using the outhouse to him is a normal, natural thing.)

So really its not as extreme as you would imagine, we have all the amenities of a normal home (except you have to go outside to shit, but you get used to that) and it takes a little more effort to turn on a light (light the flame) and to do a few other things. We have a 3000 sq. ft. barn that my wife and I built ourselves (with the help of the tractor and dozer of course), three large sheds, one of which is my workshop and a huge orchard with multiple varieties of fruit trees. We raise blueberries, raspberries, blackberries, strawberries, mulberries, service berries and honey berries. We have great hunting (turkey, squirrel, deer and rabbit), wonderful fishing just a short ATV ride away and a large garden plot where I raise enough food to keep the table filled during the summer with plenty of extra that we can for the remainder of the year.

Now all that being said, my wife wants to build a contemporary home on our upper field at the top of the ridge. We are saving up to do that. I will put in a septic and a deep well for water and probably pay to have electric poles run to it to supplement the solar that I will install. Most of it will be propane powered and wood heated like the present house.
Here are a couple of pics of the place, the first close up and the second from the adjacent mountain on our property. The last one of our barn.

It seems like a beautiful place. Good on you for preserving the history. I still don't want to have to leave the house to poop though.

Tag.

Have you considered gas (propane) lights and fridge?

tag

NICE



 

If this is an off the grid kind of deal, you're going to want to minimize your fuel use.

Reduce the size of your A/C and get a Honda EU1000.  Sips gas.  6/10ths of a gallon every 8 hours while on eco-mode.

You have one?  $300 can be good or bad with HF

I never cease to be impressed with the quality of Honda's non-automobile products.

Les Stroud built an off the grid home for his family back before he was famous, and videod the process.  Lots of cool insight that you may find interesting.  Should hopefully be on YouTube still, if you can find it.

Found it here, maybe other places as well:

http://documentaryheaven.com/les-stroud-off-the-grid/

I don't - I'm just getting along right now with a 3,000 DuroMax, which works great, BTW.

But a lot of others have given that generator head great reviews, and if I can find a good deal on a suitable motor I'm going to build one like this guy -

http://tim-yvonne.com/generator/

Since OP already has the perfect motor I figured it was worth mentioning.

I would go with a 2:1 speed reducer and drive a Lima MAC generator at 1800 RPM.  Why?  Ultimate durability, NO voltage regulator to worry about.  Dead nutz reliable power.

       
 

Thanks diehippy.....interesting and informative stuff.

And thank to the others who have posted here with info and links.

Here are the reasons I am doing this:

I don't enjoy the things that society has "trained" all of us to believe we need to be happy. Grass cut as short as my neighbors....big house with too many rooms and unneeded space.....expensive showy cars......250 channels....etc. I enjoy reading. Nature. Being alone or with my spouse. Fishing. Hunting. Farming. Seeing my kids happy.

I'm not a people person.

My kids are grown and don't rely on me anymore.

I don't like going to work when I don't feel like it.....to earn money for "stuff".

I like the idea of just working for enough money to eat and have bare necessities. I am a small engine mechanic, I can do that to earn a few dollars. I have a tractor with implements to make a few dollars....bush hog....etc.

I have no credit card debt, or car payment, or mortgage, or child support, nothing.

I have always wanted to do this.

I want to "check out of the workforce and society" now, while I'm in my 40s and healthy. I don't want to retire in my 60s, live a few years, and die.

The parcel of land this will go on is over 50 acres, and is paid for and secluded.

OK, about the cabin-

I plan on it being small, between 400 and 600 sq ft.

It will be VERY well insulated.

I am open to many construction ideas. I have a wide assortment of hand tools, electric tools, and chainsaws and log splitters. I have done all kinds of construction in my life, framing, siding, roofing, concrete work, etc.

I have no time limit.  I have a camper to live in as work progresses.

I guess that's about it.

Sounds awesome!  Check out les

Is it really off the grid if you have to buy fuel to make power? You are just replacing one dependency for another and I would guess that fuel procurement to be extremely tenuous in emergencies.



As for fuels, propane would be best since it does not go bad and has a relative decent BTU value.

My cabin is off grid:

I have a 3500 watt generator that at half load will run all day on very little gas. >2 gallons. This is for times I need the extra power. Mainly to run a large TV / DVD player for the kids and to power fans in the summer evenings. But it also doubles as my power source for power tools as I work on the cabin and out buildings.

The water system is run on one 12v battery which I can charge with a small solar panel. The water tanks are filled with a gas transfer pump from my creek.

Lighting is either oil lamps or propane lanterns.

When you decide to live off grid you have to adjust and not be hung up on electricity like a normal home. If you want a normal power usage cabin you are probably better off just paying to hook up power. It's cheaper and easier than working around for heavier use items like A/C or bigger draw appliances.

My stove is propane and I don't have an oven.

As for a fridge- it took me a while to decide not to use propane. They are expensive to purchase and while they are efficient they aren't very large compared to electric ones. My decision to run power to my barn was solely based on running a fridge. So the $30 a month power bill is about as much as propane would have cost me without the upfront cost of an expensive fridge. And I have my fridge in the barn.... Yes it might be cheating a little but with three kids I need the back up source just in case.

Oh and you won't believe how quiet and peaceful it is without all that crap beeping, running, or cluttering up your space.

Glad to see you pursuing a dream OP.

I'm curious, are you going to build out a larger workshop/garage/barn etc type structure as well as the cabin to do your engine repair etc?

Any plans for food production, plant or animal?

If you want to be truly prepped out, then you need to eschew these newfangled gasoline generators for an old reliable Lister engine.  Unfortunately Rocketboy's page went dark, but your can still see it on the Wayback Machine -

https://web.archive.org/web/20060721084403/http://www.f1-rocketboy.com/lister.html

oh boy. You must have really pissed off the wife this time.

I have done plenty of micro-generation.  Here is what I know

You need 2 shaft horsepower per kilowatt of electrical output if you want reliable performance.

The average automotive alternator (140mm stator) is good for about 2kw continuous output.

Your 16hp engine is capable of driving several alternators.  I would reduce the governed speed to about 2200 rpm which will extend life & reduce noise.    Find a 6 inch or larger diameter pulley to fit the shaft.  Alternators need to spin 5000+ rpm forfull output & best cooling.

I would strongly suggest a 24v battery bank & inverter.  24 volts was the industry standard in RE for a long time.  The inverter designs are well proven and reliable.  There is a whole world of off-grid 24v stuff out there.  12v inverters tend to be temporary standby items.

24 volt 21SI alternators are available new for around 140 bucks at your door:

http://www.ebay.com/itm/DELCO-HEAVY-DUTY-ALTERNATOR-21SI-70-AMP-24V-1-WIRE-1117915-/140300902477?vxp=mtr&hash=item20aa95e04d


A pair of those can run your 3000 watt inverter and still charge the battery bank.  A must for catching up or  equalizing battery banks.  

Generating 60hz power is a pain in the ass.  Use as much low voltage LED lighting as you can.  Most of the newer stuff has switching supplies built in,and will run from 9 volts to 36 volts without issue.  Efficiency goes UP at 24v.  Smaller wires, less current too.  24v fans are easy to find - a little muffin fan near the woodstove will spread the heat nicely.  

Inverter for the 60hz loads.  less of a pain in the ass than building a genset for most home loads.  

Now, about the construction.  Insulate the crap out of things.  Spray foam still wins this contest.  DIY kits make it easy.  I have used foam it green with great success.
 Plan for enough solar to eventually make the generator an occasional use item.  
Consider installing a Mini-splt A/C unit in the original design.  Higher efficiency from the start, and quieter in the home as well.

.