Off Grid

[smokepolehall]

We live in a 12x18 cabin, no power company. all we have is a generator & 2 battery bank so far. i don't know the total watts but i have added up the max amps if everything we have is on at same time. 27 amps. my generator is used to charge the batterys & we use for it the amount of time it takes to charge them. we have a 750 watt 6.52 amp inverter, hope to get a Vector 3000-6000 model next month. my batterys are what i can afford, Maxx series 29 125 amps from walmart.i have a 10 yr old schumacker 10 amp charger, its taking me 6 hrs to charge the 2 battery bank. i am thinking of getting the Schumacker SC-8000A 80-30<>12 amp speed charger, to shorten charging time. the gas for generator is getting into our pocket real deep. what size battry bank do i need & solar panel setup is in the future, as were on fixed income of my disabled monthly allowance, lol. Do we need to use buss bars? batterys will run parallel as the 12vdc into inverter.

[ghurd]

I would say save your money on the inverter.

The battery bank is not big enough to supply 3000W, and a big inverter like that will waste a lot more power for the small loads.

Even a 1200W inverter will seriously push those batteries.

It would not take long at all for a 75~85W class solar panel to pay for itself in gas.

Two would be better.

Should VERY seriously look into that.

G-

[madlabs]

Not saying this is ideal, but it's what I'm doing...

I took a lawnmower and hooked it up to an alternator. I can get a solid 50 amps from it. One thing that is nice is that you aren't making 120VAC and then stepping it down again to charge the batteries. If you can scrounge a lawnmower engine, it's cheap too. I got my mower from the dump, someone had backed over it ruining the mower deck but the engine was fine. For mounting, check out theepicenter.com, they sell a precut steel deck cheap. It made making my set up a snap!

For sure you need to upgrade your solar, so do I. And I will when I can afford it. Even so, you will need some sort of charger for when there isn't enough sun, so the lawnmower setup won't be wasted.

My lawnmower is a 5.5HP, and I could be getting a lot more amps out of it. I need to buy a more powerful alternator, and I think I can get something between 100-150 amps out of my rig.

[dnix71]

I second the suggestion to use a mower engine and alternator for battery boosting. It's more efficient, unless you don't have enough sun for solar panels. Can you post a picture of the cabin? Are there trees shading the roof?

You can't make electricity anywhere near as cheap as the power company. So, you can't live off-grid like you do on-grid if money is an issue.

Can you tell us what appliances you consider "must haves"? How do you get water?

LED lighting directly from 12 volts is much more efficient than using an inverter and CFL's.

[smokepolehall]

i am very interested in your lawn-mower engine set-up. i have a 10 hp gen. borrowed from a good friend. the gen. runs 2 hrs per gal. & is tuff on purse strings. does it have to be a 5.5 hp or can a 3.5 or 4 hp work ? i can get a used alternator from salvage yard. would i then run wires to an inverter or what ? this is my 1st Rodeo on this stuff. i knew my 2 batterys were not much help but i had to have power for my Cpap machine at nite to sleep. at the time my funds allowed a the 750 watt 6.5 amp inverter.thanks to all who are trying to help me. funds for solar won't break loose til May of next year.

[ghurd]

Quite possible an 80W system could pay for itself in saved gas in about 4 months.

The mower and car alternator would save a lot of gas too.

Quite a few 3.5 to 5HP B&S and a car alternator setups on here.

This is a bit different than most, but recent enough for me to find it.

http://www.fieldlines.com/story/2009/6/26/223425/021

Can save some more battery power with a smaller inverter for the night time use.

Not sure if it is the same machine, but I set up quite a few "night time breathing machines" with 175W Vector inverters.  Most of those systems powered other things too.  Most were in the 80W class.

Seems like a 50W panel had no trouble except the worst 6 weeks of winter, when he boosted the battery every few days with a B&S and car alternator.

It is good you asked.

Lots of ways to reduce the costs of how you are currently doing it.

G-

[madlabs]

It's really, really easy. Go check out theepicenter.com for the mounting bracket. He also has a circuit to drive the alternator field. It's nice to have an external field connections, but it seems that many of the higher power alts are internal regs. It's easy and cheap to get low power external regs, which is why I have one :0.

As I mentioned abaove, I'm using a 5.5HP Honda engine and a 63 amp alt. I can get 50 amps out of it all day as long as I have a large muffin fan cooling it. Otherwise it overheats. The motor isn't breaking a sweat producing 600 watts, and I think if I had a better alt I could get between 100 and 150 amps out of the 5.5 HP, probably like 120A.

My mower is a vertical shaft, and it runs the alternators built in fan backwards. Horizontal engines are easier to deal with and mount different alts to.

I'm using the RPM's to control the output, so I just have the field connection tied to the + side of the battery bank. Thing about doing it this way is you best not exceed the alts max output. I also have a cool MCU controlled controller that I made, but my current sensor got stepped on . So it;s manula control for a while.

Jonathan

[richard]

Home Power #42 August/september 1994 . Engine/Generator With Field Controller.   richard

[smokepolehall]

we haul water from the river, use a 12vdc pump and an old car battery for go juice. i have no choice about the power as eletric company want 4k plus & my cabin set onto a locked foundation blocks. plus need 60' easement across a man's place he won't give a ft. were into our early 60's & i am disabled. sure there are trees shading the cabin all morning.appliances 2.o amp 4.o cu fridge a 1.6 amp 7 cu ft freezer 3.4 & 3.8 amp laptop's. 2 20 watt Fl/24" lights a 6000 b tu 4.5 amp A/C & fan 4.4 amp & my 3.8 Cpap machine. the A/c is shut down at 9 pm & fan runs til morning. sun hits roof of cabin about 11 am. its a lofted barn bldg. we call our cabin.

[dnix71]

If you need a/c, a fridge and freezer off-grid, you are not going to be able to run that on batteries. And you will go broke running a gas generator that way.

Getting older, fixed income and needing a breathing machine at night is tough enough without being off-grid.

About the only way that won't break you financially and still keep your lifestyle is to run a Lister genset with diesel, and keep your batteries and inverter. One properly setup will only use 1/3 gallon an hour and will run all your stuff.

http://www.utterpower.com/listeroi.htm

http://www.listerdiesels.com/ are places to start reading.

This video on Youtube shows one running in Florida. It will put out 4KW all day with no effort. The generator head has to be bought separately.

http://www.youtube.com/watch?v=YGmfeNMqYVk

[bob g]

a listeroid 6/1 (6hp single cylinder diesel) will consume approx .2 gallon per kwatt/hr at (and this is important) full rated load of approx 3 kwatts.

if you are running it at low load of perhaps 1000 watts or less, it will do substantially worse in fuel economy, and require frequent decoke/decarboning.

the listeroid is not something i would recommend to someone that is not mechanically

inclined, the learning curve is only made steeper if you are depending on it to survive while you are working the bugs out of it.

and they all have bugs to work out, some worse than others.

bob g

[zeusmorg]

 Another way to save expenses If you build a "lawnmower charger" is to run it off propane. If you search around, you can find how to convert a gasoline engine to run off propane, and your savings may be significant. I'd look around for an old gas grill, It would have most of the components you'd need for conversion which is mainly the regulator, and those seldom go bad on a grill.

 I do agree with everyone here, you could easily save money going solar, or some other form of generation, It really depends on your resources available, do you have a creek nearby? Hydro is probably the biggest overlooked natural resource we have, and it's usually pretty easy to use. Also what are your wind conditions? Do you have enough wind to justify building a mill? Even a smaller version would contribute a lot IF you have decent wind.

 It already sounds like you're quite minimalist on your power use. You could also look at efficiencies of how you do things. Like 12v lighting and appliances vs 120.. If you can use some 12v, then your efficiency would increase by 10% on any that you use off the battery bank. (approximating) Of course you DO need to keep any 12v wiring runs as short as possible.

 When it comes to efficiency, every step you take to convert energy has losses. So it's best to use less conversion steps where possible. 12v florescents are available, as are some small 12v appliances. Look at your local truck stop or talk to a trucker friend.

 I know what it is like to live on a fixed income and it is NOT easy! So every dime you save can benefit in the long run. You may even consider getting a short term loan for some panels, If you talk to your local bank, and explain exactly what you are doing they may consider a small loan for them!

 Id seriously look at your other available resources and think about how you can convert or use them for your needs.

 

[bob g]

my bad, got to thinking and remembered

the 6/1 will do 1/8 gallon per kwatt/hr generated at full load (3kwatt)

and closer to 1/5 gallon at 1kwatt load.

even if you had one lumbering along all day making 1 thousand watts on average

it would consume a fraction of the fuel you are burning now.

the downside is they are not an out of the crate plug and play proposition.

the OP might be better served by another small diesel engine, even if it did a bit

less in fuel economy, many such as the changfa's are more of a plug and play project, and are generally much lower in first cost.

if it were me, and it will soon be

i would size a larger engine/genset so that it could run maybe a couple hours per day max, during which time it can not only charge my battery bank from 50-80% but

also provide AC power for my heavier scheduled loads, and

make domestic hot water in the process, which is nice to not only wash clothes with

but soak and old acheing body.

if your gonna live offgrid with engine/gen power, you gotta think diesel and cogeneration, and have enough battery capacity to allow you to shut down and coast for significant amount of hours per day.

bob g

[bob g]

if i might be so bold?

what part of the world are you from?

if you are close enough, i might have some stuff that you can use on a loan basis.

i could use an offgrid test bed for some things i am working on, of which you look in real need of.

bob g

[smokepolehall]

we live n Howell county Mo. in the foothills of the Ozarks. no creek closer than the river. no water on our place. not much wind either. so we will build a solar system & battery bank.

[divemaster1963]

hello there

I have a sugestion for you. I am setting up On short purse string to. If you have the time. try talking to local battery distributors in your area. let them know what you are doing. I have found a couple of dis. in my arear that have kep a Eye out for good used high capacity batteries for me. they found me several golf cart batteries. the trogen ones t105's that were still good. they may let you have them for core charge. 5-15 dollars each. that can get you started on a better and maybe bigger bank. then keep I out for deals from PV dealers with closeouts on panels.

check with local rv or fire departments that may get hold of good used gens that where just up graded by the previous owners. I have four banks now. ( 6 12 volt gem electic car batteries, 16 6 volt 36amphour backup emergence light batteries, and 6 t105 trogen batteries. a HP 45watt panel set, 3 ecm wind mills). In all I have 325.00 In cost for eveything. including towers. And controllers from ghurd that I purchased. THANKS GHURD!! :YOUR a mentor.

go sun and good wind are the best.

divemaster1963

[RogerAS]

smoke,

you wrote;

"Maxx series 29 125 amps from walmart."

You need to be aware that if you charge any flooded L/A battery above the c-20 rate it will not last long. Your batteries together are 250 amp hours. Divide that by 20 and you get 12.5 amps. Unless you are consuming the excess amps and you change these above that rate you risk plate warping and electrolyte loss. Neither is good. Also in summer you can see thermal run away where battery temperature goes through the roof and they self destruct in minutes, and maybe explode.

Stay away from a bigger inverter until you can up scale the battery bank.

The lawnmower/alternator will work, but you'll still have to stay below that 12.5 amps if you want the batteries to last. You might be able to get away with 15-18 amps, but much more than that will result in tears.

I bought a Kubota 300 from a man in MO(see below) that gets them from the army as pulloffs from tank recovery trucks. These are nice little diesels and use very little fuel. I don't know if he still has these engines, but it would be worth a call, as I think he was selling these for $450 and they retail for 3 times that. He isn't that far from you, and was/is a good guy. I've ran mine for 3 years now and love it.

See this posting from my diary. The listing on ebay is dead within that thread.

http://www.fieldlines.com/story/2006/7/24/14246/2100

Take care and keep us informed as we may be able to help.

Craig W Wiles

6502 Mings Dr

Mountain Grove, MO 65711-3081

(417) 453-6362

[hvirtane]

It would be maybe best to buy a small Chinese diesel generator. And try getting used cooking oil (from a local kitchen/hamburger place) to be used as the fuel for the gen set. You can mix in the cooking oil kerosene to get your machine working with it (and of course put it trough a cloth to purify). That fuel would be much cheaper than gasoline.

Still investment for some amount of PV might pay. But if there is a lot of shadow from trees it might make a big difference.

It is always best to look at the consumption.

Is there any way you could keep the refrigerator somewhat naturally cooled? Insulating it outside might help a lot as well. It would probably help to use for lighting 12 V fluorescent and led to save power. If you need to cool the cabin with fans inside, it would make one of the biggest savings on power to take care that the sunshine isn't making it hot during the daytime. White (or even reflective) gardens on the windows to reflect sunshine out. Walls in the sunshine outside with white (or even with reflective) coatings. With laptops big amounts of power is wasted for cooling them with electric fans. I'm experimenting with a stone plate cooled with water bottles under the laptop (lol).

You might try getting used discarded car batteries free from recycling places. If the battery bank is big enough you don't need to drive it flat, and even car batteries would work.

- hv

[Bruce S]

How far from West Plains are you?

There used to be a really nice Pops that owned a "sale barn" over there a few years back.

Me and the lady are both from a few little places East of there (PB and Kennett).

Any way if he's still there go see of he still has the little lawn tractor for sale, it was diesel powered, small engine but sipped fuel. I would'a bought it last time I was "home" but drove car instead of suburban . It looked terrible with rust cancer, but started and held a good torque, so engine will be good along with electrics and 4 wheels to move it around.

Another gent close to you "Nothing To Lose", but haven't heard from him in ages. He used to post here a ton, if he's reading he'll be able to help a bunch too. He's really good at doin with what's around and can offer a few of the batt packs I've sent him.

Honestly with what you're needs are I would say at this time, go the diesel route and NOT solar, the expense for Solar will dig real deep into pockets, plus little diesel engines can be had pretty easy around the farm COOPs, just ask.

Batteries too, most will have older tractor or Combine batteries that still have life in them, just not so new.

Older washing machine pumps are not self priming but once primed and running will fill a tank toot-sweet.

Hope this helps

Bruce S

   

[hvirtane]

I think that it would be best to use an induction generator to produce electricity. It produces the same current as available in the grid. You can charge your batteries by using a normal battery charger and use the electricity as generated directly for other appliances. So it would probably be more economical than to use an alternator from a car.  

You can make an induction generator of an electric motor running by a gasoline or diesel engine. Some basic information is here:

http://users.telenet.be/b0y/

Some practical information here:

http://www.qsl.net/ns8o/Induction_Generator.html

So I think that the economical way would be to use a diesel engine to run an induction generator. As fuel you could use biogas, too if you can get material to put in the digester. Grass, cow dung...

- hv

[Ungrounded Lightning Rod]

Just a random thought:

You might want to check the construction equipment rental places to see if they have any old arrow-board construction warning signs that they're junking.  The old ones had diesel generators designed for continuous use while the new ones have solar panels and batteries.  It might be a good place to pick up a COUPLE (one for backup) used diesel generators cheap.

(I have no idea how much power they put out, at what voltage, what efficiency, or their expected lifetime and maintenance requirements.)

[Fused]

Hi everyone,

I just received a spread sheet with SoC from JCI (johnson Control) yesterday on these Maxx-29 marine batteries. I simply called the 888 number on top of the battery. heres the charging specs they gave.

Bulk 14.4v-14.8v

Equalize 16.0v-16.3v

float 12.9v-13.1v

Although Im not going to push mine past 14.8v equalize.

Maybe it can help.

Good luck

Fused

[dnix71]

http://www.gensetcentral.com/lister-petter_8kw.htm

Here is an 8KW Lister-Petter genset new, load tested, on skids, warranty, FOB Kansas City.

That would run everything as cheap as it gets.

[ghurd]

I still believe solar is very worth while in a system like this.

When the batteries reach a SoC where the diesel is only making 3 or 5A, the solar can do that, without fuel, noise, or maintenance.

Must be another of the geographical anomalies.  A decent small diesel around here is worth a fortune.

NTL?  You still here???

G-

[bob g]

i would disagree that anything over a c20 rate will shorten the life of the batteries.

most quality batteries can tolerate up to 25% of capacacity charging, if

you back off of them when they reach gassing (about 80-85%)

at the c20 rate, surely the batteries will last a bit longer, but at what expense?

if you are charging with gas/diesel, you will exceed the replacement cost in fuel

much sooner than the loss of the battery.

bob g

[jclaudii]

I see your from MO, you might check out the  government liquidators at http://www.govliquidation.com/auction/view?auctionId=2509391&convertTo=USD

I have seen these 5kw compact diesel genies go for as little as $175 bucks.  Since it's diesel, I bet you could find a way to convert it to run on Veg oil.  I know it's a risk, but if it falls through and the engine is no good, you might have a good gen head.  If both fall through, you have spare parts for the next one you buy.  Most stories I have read people get ones that work.  

I know this is a longshot, but call up your local cable, telephone, cellular phone, internet, and any other "techie" business or service in your area and ask about taking their UPS batteries off their hands when they do a upgrade or refresh.  I have a couple of the guys at my local telephone company keeping an ear out for me.  

Let us know what you decide to go with.  

But on a side not you ask a question about how you hook the car alternator running off the briggs engine to the batteries, you bypass the battery charger and the inverter hooking it up directly to the battery.  Your basically using it like how it works for your car.  With an amp meter you could keep your engine running at the perfect amperage and perhaps save some fuel and your batteries at the same time by not running it at full blast.  Their are different types of alternators, and if you decide to go that route ask us and we'll help you out there as well.  

If you need hotwater, try and use the heat of the engine to warm up some water in an insulated 30gal barrel by using the exhaust or some copper pipe and hose touching the engine.  You can supplement that by  using some black hose on your roof or on a collector to get and store "extra" hot water.  

For the lights, get some LEDs from an online supplier, i know some, and I'm sure others have some they use, but for 12v use.  You can then run a 1-2 watt load on your 12v's when you need just some light at night.  

[Photowhit]

Your laptops will not be drawing 3.4 and 3.8 amps at 110volts running. might look into borrowing a Kil-a-watt meter to check the actual draws of te appliances, the fridge and freezer aremax draws as well and since they run off a thermostat they will draw tiny amounts of electric most of the time.

A Kil-A-Watt meter will give you daily draws for apliances.

A gas power DC generator is a fine idea, but I'd be careful not to get too high a charging current. Likely you don't want to charge faster than 1/20th of you rated amperage or you can damage the batteries. so maybe 25 amp charger would be fine for 2 - 125 amp batteries run together.

[Photowhit]

Math problems

Anything above 12.5 amps might damage batteries.

[Photowhit]

Eualizing is an important part in keeping batteries healthy, that said 16+ voltssounds a bit high, but I'd listen to them. I do a 2 hour equalizing charge every month, I think I'm using 15.5 (31 volts 24 volt system) with golf cart batts. If you have a charge controler with a battery temp sensor typically it will prevent heat damage.

Any who worth read about...

.

[Photowhit]

Ooops also need to say, I check the SG (specific gravity) at least twice a year (use to do it monthly) and watch the equalizing to bring battery cells up to a standard.

Just things to think about, I should be checking monthly now as my batteries age, but an under sized 4 year old set of golf cart batts(just 4) that I torture in the summer running an A/C ain't too bad.

.

[smokepolehall]

i am sure that its going to be the small engine - altn. set-up, i am trying to figure out the right way to hardwire battery bank to inverter. i decided not to get the 3000 watt but the 2000 should make it. i hope to have 750-1000 amp bank by spring. have 250 now & getting another new battery aug. 1st along with the parts for this project. thanks everyone. i will still be asking ?'s and help over this project.

[smokepolehall]

will the Honda GC 160 5 HP horizotal engine work ok ? i can buy a new one reasonable.

[Yyrkoon]

In short, yes it can. I have no idea of the plate the epicenter uses mounting wise, but the 5 horsepower engine will power up to a 100A alternator easy. Of course, 100A is too much for two batteries for a major amount of time. Anyways you get roughly 745.7 WATTS per horsepower( including losses and all that ), and there are some losses concerning belts/pullies. A lot of the generators we get in our shop here also seem to double the horsepower needed to drive a given GEN head, so you're covered there as well. I assume it has to do with keeping he engine load at a manageable/reasonable level, but I could be mistaken. All of these are direct drive, so there are no drive losses.

I'd also have to say I think Honda small engines are some of the best. So much so, that  there are many knockoffs of their engine designs. Briggs&Straton, and Subaru make decent engines as well. We own a small engine shop here, and to be honest we do not see many vertical shaft engines because we repair mainly Generators that use horizontal Shaft. We do however have a Honda powered pressure washer(VShaft) that works pretty good with minimal maintenance.

I myself, have been toying with the idea of making a  dual rotor air core alternator to direct drive on a Honda GX360 . . . and make sort of a pancake head generator. We'll see how that works out in the future though ; )