Generator, batteries & power supply

[MrL1A1]

Ok, lets say I got my generator but I do not want to run it all the time....but I need semi-long term power (enough to run the fridge, a couple lights and a small heater fan). How can I incorporate batteries in the equation ? Would 6 or 8 car batteries charged off the generator every fews days be enough to run my appliances? This way I could save fuel and $$$ and always have at least some juice

 

[Indycar]

You would need to incorporate an inverter into the situation. Batteries are DC appliances are AC. An inverter changes DC into AC.

 

[MrL1A1]

Is that hard to do and are they expensive?

 

[edporch]

If you try something like this, you wouldn't want to use car batteries.
You need to use deep cycle batteries instead.
Car batteries aren't designed to be discharged to the degree that an application like this would do.

You also would need a large amount of battery capacity to run an electric fridge, lights and a small heater for a few days.

I have a little bit of personal experience with this.

In my case, I have a cabin in the woods and there's no electricity.
I didn't want a generator making all that noise whenever I wanted electric power.
I wanted to have basic lights, music (an old laptop computer with a music library on it),a small stereo amp, radio, the ability to charge battery packs for cordless tools, etc.
I even wanted to run one of those large coolers that run off 12 volts.
More importantly, I wanted this stuff to be available 24/7.

After doing this for a few summer vacations, I arrived at a solution that works OK, and doesn't require a large battery capacity.

I have two Trojan L16H 6volt 420 amp hour deep cycle batteries wired in series for 12volts.
These batteries weigh about 120 pounds each.

I have an 1100 watt Exeltech pure sine wave inverter connected to them.
I went with pure sine wave so there wouldn't be any issues with plugging things into it that don't like non-pure sign wave AC.

I use 7 watt fluorescent screw in light bulb replacements for lights.
I found that even the small electric coolers pull between 5-10 amps at 12 volts.
This and especially if somebody else brought one along, really drew the batteries down when run 24/7.

So I use an old propane powered refrigerator/freezer out of an old RV to take my refrigeration off of the electric circuit.
It will run 24/7 for about a week and a half on a full 20 pound (gas grill sized) tank.

If I need heat, I use a kerosene heater, or burn wood in a small stove.

For cooking, I have a big tank of bottle gas outside.

So now I can run my system for 2 days between recharges if I don't waste energy. (I usually charge every day so I don't discharge the batteries as far, thus extending their life. They 'aint cheap LOL )
It consists of 7 watt fluorescent lights, an old laptop computer, an old Marantz 1060 30 watt per channel amp, a fluorescent shop light for an outdoor light when needed at night.
I try to charge any cordless tool battery packs when I do my main batery charge.


So now you ask, what does it take to fully charge these 2 Trojan L16H 6volt 420 amp hour deep cycle batteries wired in series?

I have a Honda 6.5hp motor, with a modified 65 or 70 amp (I forget which) Delco alternator.
IT'S MODIFIED SO THAT IT DOESN'T USE AN INTERNAL VOLTAGE REGULATOR, BUT INSTEAD WIRED TO ALLOW ME TO CONTROL FIELD CURRENT EXTERNALLY.
MY NEIGHBORHOOD AUTO ELECTRIC SHOP DID THIS FOR ME.

IT'S IMPORTANT THAT YOU DO THIS, BECAUSE IF YOU JUST HOOK UP AN ALTERNATOR WITH THE STANDARD VOLTAGE REGULATOR TO DEEP CYCLE BATTERIES, YOU RISK EXPLODING THE BATTERIES WITH THE HIGH CURRENT THE ALTERNATOR WILL PRODUCE (BECAUSE IT'S NOT BEGINNING THE CHARGE REGULATED BY CURRENT INSTEAD OF VOLTAGE), OR YOU WILL BURN UP THE ALTERNATOR.

Just for this pair of batteries, I need to begin the charge cycle with 40-50 amps. (plus a little more to account for any current being drawn in the cabin from the inverter, which for each 1 amp of AC, it pulls about 10 amps from the battery bank)
It runs at the level of amps until the battery voltage reaches 14.8 volts, then the current is backed down gradually as the batteries charge to keep the charging voltage at 14.8 volts.
So you can see that it's easy to run the alternator at close to it's rated capacity pretty easy.
The good thing is, it's not in a hot engine compartment, so that helps.


So say I would want to double this battery bank?
Already the small Delco alternator won't have enough capacity to properly charge the battery bank, as I would then need 80-100 amps.
And the 6.5hp motor would be getting close to not being big enough.

I'm planning on going to a battery bank of four L16H batteries in the near future, so I recently upgraded my alternator to a Leece-Neville 165amp externally regulated alternator.
These are pretty expensive.


So getting back to your idea of using your generator to charge a battery bank during the time you have it running?
Imagine the size of AC generator it would take to run an AC battery charger big enough to charge these?

Anyway, MY POINT in writing all this is to make the point that what you're wanting to do is a bigger project than you would think.

I know when I started down this road back in 2000, I had no idea it would take as much as it has, just to have 420 amp hours @ 12volts capacity.

I have thought of messing with some solar panels in the future, but haven't yet, because the cabin is in thick woods, and there's not enough sun.

 

[MrL1A1]

wow...awesome post :beer:
Sounds like you have a nice setup at the cabin. To be honest I was unsure about what kind of feedback I would get here in regards to the battery bank idea. I guess I have watched to many old b/w WWII sub films with the guys traveling around the world on batts (diesel recharge).

I am going to look into those deep cycle batts

 

[edporch]

wow...awesome post :beer:
Sounds like you have a nice setup at the cabin. To be honest I was unsure about what kind of feedback I would get here in regards to the battery bank idea. I guess I have watched to many old b/w WWII sub films with the guys traveling around the world on batts (diesel recharge).

I am going to look into those deep cycle batts

Yes, it works out pretty good up at the cabin.
I have it mounted in a 14 foot, dual axle, ramp, Wells Cargo trailer that I use to take stuff up there.
Then I just run a long 10 gauge extension cord out to the trailer and plug into the inverter.

The cabin at one time had electricity, so it is wired.
I just got into the fuse box and wired in the extension cord.

Besides having basic power 24/7, it's so much nicer to be able to relax in the woods, and not have to listen to a generator running all the time.

Course, if a person was in an area where there was sunlight, they could use some solar panels, and not have to hear a motor at all.


Here's some info on the batteries I use.
http://www.trojanbatteryre.com/PDF/datasheets/L16H_TrojanRE_Data_Sheets.pdf

Go here and download the "Product Specification Guide"

http://www.trojanbattery.com/pdf/TRJN0111_ProdSpecGuide.pdf

Note that the L16H is the best of the L16's as far as capacity.

Trojan also has a place on the home page to find a dealer near you.
http://www.trojanbattery.com/Index.aspx

These batteries are so darn heavy that you'd pay alot to have them shipped.

A note on deep cycle batteries.
You'll see batteries being sold as "deep cycle" that aren't really true deep cycle batteries.
A simple thing to look for is whether they have an "amp hour rating".
If there's no spec listed, it's likely not a true deep cycle battery.
(I had people pull this on me when I first went out to buy batteries and wasn't sure enough about what I was doing)

A note of caution again.
If you decide to get into charging deep cycle batteries, make sure you have the right kind of setup to avoid hurting yourself.
Just NEVER try to charge them with a standard voltage regulated alternator.
I see places on the Internet telling people to do that, and it makes me cringe.

In fact back when I first got into this, I tried it too, not knowing any better. LOL
Lucky for me, the current surge from the alternator, trying to output enough current to bring the voltage up to it's setpoint, put such a load on the motor that it killed the motor instantly. LOL
I didn't realize til I went "back to the drawing board" to learn what was going wrong, that I could've exploded the little battery I was attempting to charge.

If you have any questions, please fee free to get back with me.
I'm sure there are tons of people out there who know alot more than me about this, but I do know some basics.

 

[xdshooter]

very cool, I think many people with a cabin would like to try this. But I have three questions.
1. How did the local electronics shop get the adjustability on the alternator? 2. Why wouldn't the small alternator just take twice as long to charge the larger sized battery bank? Isn't a slower charge rate better for your batteries anyway, besides the fact that the alternator would be spinning longer and the engine running more?
3. Do you have to check the fluid levels of the batteries?

thanks
xdshooter

 

[edporch]

very cool, I think many people with a cabin would like to try this. But I have three questions.
1. How did the local electronics shop get the adjustability on the alternator? 2. Why wouldn't the small alternator just take twice as long to charge the larger sized battery bank? Isn't a slower charge rate better for your batteries anyway, besides the fact that the alternator would be spinning longer and the engine running more?
3. Do you have to check the fluid levels of the batteries?

thanks
xdshooter

Good questions.
There's really so much stuff about doing this that I didn't touch on.
What started as a simple thing to have a simple 12volt battery to run my "ghetto blaster" and bagphone, has grown into this.

I'll try to give some basic answers.
This whole thing is actually something that a book could be written on.

Basically, I was inspired by this great article:
http://www.homepower.com/files/webextras/mark8.pdf

I have a friend who does metal fabrication, and he welded up a design I made based on this article, so I could mount my motor and alternator to it.

1. My local auto electric shop simply modified my alternator so that on the connector, I had direct access to the field.
(If you could find an alternator that is already of the external regulated type, you could skip this step)
I assume the other end of the field is grounded to the alternator case, because I just apply adjustable current from the battery to this one lug in the connector, and the circuit has to be through the alternator case. This way, I can externally apply current to it to adjust the amount of output current the alternator.

I still just manually apply adjustable field current with a big rheostat connected to the batteries, and watch the charge current and charge voltage as they charge.

The reason I haven't built the Mark8 charge controller, is partly laziness, but mostly because it doesn't charge in a way that takes into account the actual net charge current going into the batteries.
i.e. If things are adding load in the cabin, I'm not actually charging the batteries as much as I think I am.
I'm an electronics person, and have been thinking over ideas on making my own charge control circuit that charges the batteries based on net charge current to the batteries.
But since this is just a vacation cabin that I'm not able to spend tons of time at, this charge controller circuit always gets pushed back in the list due to always pressing immediate things.
In fact it's become a joke with my friends about my still using the rheostat to manually control the charging.
I realize I could probably find a "store bought" charge controller that would do this, but I'm sure it would be relatively expensive, and most of all, I wouldn't be able to repair it myself when it eventually had a malfunction.

2. You're right in that you don't want to charge batteries too fast.
But even charging at a rate of 10-15% of the amp hour rating (check the specs on your batteries to see how fast you can charge them without damage), it takes SEVERAL HOURS to fully charge the batteries.
Plus, you need to have the charging capacity to do an "equalization charge" every now and then as needed.
If you greatly reduce the charge current, it greatly increases the charge time to a point of ridiculous.
Which if one was using solar panels or a windmill, with a charge controller, so that it doesn't have to be watched, or making sure a motor doesn't run out of gas, that probably would work alot of the time.
But in my case, where I'm in the woods, there's no appreciable sun, and carrying a windmill up there is impractical, even of there was wind.

3. I check the electrolyte levels in the battery according to the manufacturer's instructions found here:
http://www.trojanbattery.com/pdf/TRJN0109_TRJNUsersGuide.pdf

 

[xdshooter]

thanks, that is a very good read. I was guessing rheostat all along.

I've had an idea kicking around in my head to do a charging windmill, that puts the alternator(s) and control circuits in a small shed at the base of the windmill. Sort of like an old farm windmill, but instead of a pumpjack, the windmill sends it's power down a driveshaft to a bank of pulleys and alternators. The key would be getting a hall effect sensor to monitor speed, and increase and decrease the field current to keep the rpms within a range. That way, you could trickle charge in a slight breeze, and fast charge when the wind really blows. OR when the batteries are full, and the ambient temp is below, say, 50 degrees, dump into a heating element inside the house.

once again, thanks, this adds a bit of info to my brain that it needed!

later
xdshooter

 

[edporch]

thanks, that is a very good read. I was guessing rheostat all along.

I've had an idea kicking around in my head to do a charging windmill, that puts the alternator(s) and control circuits in a small shed at the base of the windmill. Sort of like an old farm windmill, but instead of a pumpjack, the windmill sends it's power down a driveshaft to a bank of pulleys and alternators. The key would be getting a hall effect sensor to monitor speed, and increase and decrease the field current to keep the rpms within a range. That way, you could trickle charge in a slight breeze, and fast charge when the wind really blows. OR when the batteries are full, and the ambient temp is below, say, 50 degrees, dump into a heating element inside the house.

once again, thanks, this adds a bit of info to my brain that it needed!

later
xdshooter

Sounds like fun.
I'd like to get more into using nature to charge batteries at some point.

Though I have no personal experience with using an alternator in a windmill, I have read that a standard automotive alternator loses a lot of efficiency because even when sitting waiting for wind.

Your design sounds interesting and could cut down on useless field current when there is no wind.
Do you know how much current it would take to run your control circuit when in standby (waiting for wind) mode, or how much it would take when in trickle charge mode?

One idea that just hit me on this.
What would happen if you had a small spring loaded flap, that when there was a preset amount of wind blowing over the windmill, a small switch would be closed by the flap, that enabled power to your control circuit?
That way there'd be no current loss when there was no wind, or wind velocity below a given set point.

There are permanent magnet alternators (PMA).
I have no idea how expensive they are, or what drawbacks they have.

There is an old article from Homepower Magazine where they made their own.
Here's a link to the story:
http://www.otherpower.com/wood103.pdf

I think in my case, I'm going to experiment with solar panels first, because I can just carry them in my cargo trailer with the rest of my system, and if I'm somewhere there's sun, pull them out.

 

[mosbysmen]

pictures would really make this post ,great

 

[xdshooter]

What would happen if you had a small spring loaded flap,

hmmm, that does sound like a possibility, I guess my thought was that you could run a small circuit to monitor a hall effect sensor, that sends a voltage to a relay only when a desired speed is attained. I am not the electrically minded, but I have a few electrical engineers in the family.

I guess I wasn't really worried about not having wind. The high plains of South Dakota where I grew up, where I will be installing this, don't go more than a few hours without wind. I did a little geographical research, and my site has one of the tallest hills outside of the Black Hills, in the entire ND, SD, MN, NE, IA, area. Right at 3000 feet.

I am hoping to be able to put up one larger grid tie windmill, then run several smaller, cheaper, redundant, off grid windmills for grid down situations, and do cut my grid use to almost zero. Solar would work fine, but I think there is more energy to be had for the investment in wind this far north.

later
xdshooter

 

[edporch]

pictures would really make this post ,great

Here's a few pictures from a couple of years ago, before I mounted the batteries in the trailer.

As I said earlier, I as inspired by this article I found from Homepower Magazine online.

http://www.homepower.com/files/webextras/mark8.pdf


My own motor/alternator battery charger.
http://www.rensseltucky.com/power/IMG_3164-8x12.jpg

NOTE: Unlike the Homepower article where they mounted the alternator from the other side of the belt, in order to preserve the stock rotation direction of the alternator, I mounted my alternator on the same side of the belt as the motor.
I think it gives a more compact installation.
But it has the drawback that the alternator is now rotated backwards.
In doing this, I needed to get a bi-directional cooling fan. (The part mounted just behind the pulley)
It makes no difference which direction the alternator is rotated, as long as it has a proper cooling fan designed for the direction of rotation is used.


A typical time charging the batteries.
Square gray box houses the rheostat that I use to adjust field current to the alternator.
This controls charge current.
http://www.rensseltucky.com/power/IMG_3162-8x12.jpg


A view of the voltmeter and ammeter I use to monitor the charging voltage and current.
http://www.rensseltucky.com/power/IMG_3160-8x12.jpg


A view of the 2 series connected Trojan L16H 6 volt deep cycle batteries.
http://www.rensseltucky.com/power/IMG_3161-8x12.jpg


Hope this gives a better picture.

 

[MrL1A1]

Glad this became sticky. Lots of excellent info! :beer:

 

[jimbeam]

TAG

 

[izaakb]

I am planning a generator setup for the whole house..

What I am ignorant about is the best fuel to use: i.e. gasoline, diesel or LPG/NG.

My issue is long-term storage of the fuel. Gas breaks down, even with Stabil in it after a while. I'd like to keep enough on hand for a few weeks of use, which means hundreds of gallons of fuel.

Seems to me a large LPG tank is easy to install and conceal, and the gas "keeps" for long times.

I don't know about diesel at all.

anyone?

 

[edporch]

I am planning a generator setup for the whole house..

<snip>

My issue is long-term storage of the fuel. Gas breaks down, even with Stabil in it after a while. I'd like to keep enough on hand for a few weeks of use, which means hundreds of gallons of fuel.

Seems to me a large LPG tank is easy to install and conceal, and the gas "keeps" for long times.
<snip>

If it was me, I'd use LP.
An example, a friend of mine's dad had a microwave tower on his land that the company paid him rent.
They closed it out some years ago, and inside the building on a skid was a generator to power the tower when the power went out.
They gave it to my friend's dad.
It was powered by a small block Chevy, that ran on LP.
The thing sat there for years with minimal maintenance, and automatically started and ran for awhile about once a month.

My friend's dad still has that generator.
I'd go with an LP powered generator if I was serious about having something that might sit for a long time that when needed had the best chance of working.

 

[izaakb]

If it was me, I'd use LP.
An example, a friend of mine's dad had a microwave tower on his land that the company paid him rent.
They closed it out some years ago, and inside the building on a skid was a generator to power the tower when the power went out.
They gave it to my friend's dad.
It was powered by a small block Chevy, that ran on LP.
The thing sat there for years with minimal maintenance, and automatically started and ran for awhile about once a month.

My friend's dad still has that generator.
I'd go with an LP powered generator if I was serious about having something that might sit for a long time that when needed had the best chance of working.

good info. the LP generators I've seen for sale, tho, are limited to about 10-15kw is that a practical max or do i just need to look more?

looking for something about 20kW

 

[edporch]

good info. the LP generators I've seen for sale, tho, are limited to about 10-15kw is that a practical max or do i just need to look more?

looking for something about 20kW

I don't have an answer for you off the top of my head.
I've never done any real research on this, other than just basic observations.
I would just say "Google is your friend...". LOL
(that's where I'd start, with the Google Advanced Search)

 

[izaakb]

This is interesting:

http://www.generatorjoe.net/product.asp?0=542&1=203&3=2952

"tri-fuel" generators, gasoline, LPG, or NG.

 

[Timber Wolf]

looking for something about 20kW

That seems like a lot of power. I have 10kw (Lincoln welding machine) and it seems like plenty for most anything I can imagine needing a generator for. Why 20?

 

[izaakb]

That seems like a lot of power. I have 10kw (Lincoln welding machine) and it seems like plenty for most anything I can imagine needing a generator for. Why 20?

Because it will do the job and leave plenty over for other purposes. Did you read the thread? This is for a whole-house setup, which includes a workshop.

 

[Timber Wolf]

Because it will do the job and leave plenty over for other purposes. Did you read the thread? This is for a whole-house setup, which includes a workshop.

Yes I read your thread, and it did not say anything about doing the job with plenty left over or about including the workshop. If you need/desire 20KW go for it. It will be expensive, both to purchase, maintain, and to run. You are concerned about fuel choice because of having to store a great deal of it but want a unit that seems to be sized larger then what I think is needed and will not be very efficient.

My 10KW unit is almost twice the size of most portable units I see (5-6.5KW) out there and with a little planning will keep the freezer and fridge cold with power left for hot water and some microwaving for the few hours a day I would run it. We will not get to have central AC or the electric range, hey this is a black out, some things will have to go. I make sure to keep a few full propane bottles on hand all the time for cooking and have radios, lights, fans, and even a TV (until they go completely digital) that run off 12v power. I do not plan on working in the shop while the power is out but if I do it will be during the day when generator power is not needed in the house and I could devote the whole 10kw to running power tools.

I would like to see a break down of the wattages you reasonably think you will be running simultaneously. Does all that add up to any where near 20KW?

I sleep good knowing I have "only" 10KW in the garage for emergency power and think I will get a lot more use out of it as a welder then I ever will as a generator.

 

[izaakb]

I didn't mention it before, but I also want to use this as alternate power from the county power. NG prices are reasonable and from what I've read, the efficiency of a 20kW unit is better than two 10kW units.

I have a pretty big house too, which is part of the problem, I don't want just the fridge and a few lights going. I have two deep freezes and a few other things I'd rather not lose. Plus, I need enough power to work on top of it.

I figured 12-15 kw is enough, but 20 seems smarter from efficiency.

 

[gunsmoke]

BATTERIES & OTHER NEEDFUL THINGS:

http://www.eastpenn-deka.com/default.aspx?pageid=366

http://www.go-ev.com/PDFs/BattEQ-Summary.pdf

http://www.victronenergy.com/content.php?extraid=11

http://www.victronenergy.com/content.php?extraid=11