# Generator & Battery Bank ???'s



## Guest (Feb 22, 2011)

I posted the thread hybrid generator & battery bank . I know very little about solar system equipment & although I won't be using solar I'd like to know if the same basic equipment would be needed with the exception of solar panels ? To keep this discussion from getting confusing I'm only going to ask a question or two at a time although I have many more questions . When I get an answer to the question I just asked I'll move on to the next question . I feel by doing it this way I can avoid a lot of unnecessary questions . TIA


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## TnAndy (Sep 15, 2005)

Is one of those confusing questions "what is your first question ?"


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## Guest (Feb 23, 2011)

My first question was , if the same type of equipment would be used in a generator & battery bank system as in a solar panel system ?


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## trkarl (Dec 15, 2009)

WV Hillbilly said:


> My first question was , if the same type of equipment would be used in a generator & battery bank system as in a solar panel system ?


It depends. If you have a solar system without an inverter like say a 12v only system then you will need to buy a battery charger to use with the generator.

If you have a solar system with an inverter that has a charger built in then you will just need to wire the inverter to the generator. A friend of mine has a system which is basically a whole house UPS. It consists of an SW4024 inverter and 880 amp/hrs in golf cart batteries. 

It is run through transfer switches and plugs so the inverter can be either powered by the grid to charge the bank or a genny.

In a solar panel system you would need a charge controller for the panels themselves. This is different than a battery charger or inverter/charger.


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## Guest (Feb 23, 2011)

I am not going to have solar panels . I have free natural gas that I would use to power the generator . I would use a battery bank so the generator would run as little as possible to save wear & tear on the generator . Instead of the batteries being charged by solar panels , they would be charged only from the generator . By the way , I would want to convert the DC from the batteries to AC so I would need an inverter .


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## mightybooboo (Feb 10, 2004)

Then you should get an inverter with a built in 3 or 4 stage battery charger. That would cover you very well.

Something like this would work....
http://www.donrowe.com/inverters/prosine_inverter_charger.html

or a 3 stage charger with a separate inverter added later?

12 Volt TRUECHARGE2 BATTERY CHARGERS-
20 Amp 12V- $275.00
40 Amp 12V- $365.00
60 Amp 12V- $575.00
Click for more info

http://www.donrowe.com/battery_charger/battery_charger.html
-------------------------
Charger explanation
http://www.donrowe.com/battery_charger/samlex_document.html


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## Jim-mi (May 15, 2002)

Thats super fine and dandy to have unlimited fuel (gas) . . . 
But why run that nice ($$) gen on a nice sunny day . .?!?!


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## byexample (Aug 28, 2009)

There are 2 approaches that I can think of that would meet your goals:

1). As someone else suggested, get an inverter with a built-in battery charger. I really like the Magnum inverters and I think they will still ship for free. This is the more expensive approach, more than likely.

2). Purchase separate inverter and charger. There are a variety of inexpensive inverters to be had out there. We just retired a $150 2000 watt modified sine wave inverter from Harbor Freight after 5 years of continuous usage. That was a real deal. And there are a variety of chargers to choose from. At present we're using a portable 40 amp B&D battery charger that we bought from WalMart for about $75 I think. Getting ready to install a new battery charger from Xantrex that will give us faster charging and can be permanently installed in the system. Cost is around $350 for the new charger.

We have been saving and planning to upgrade our 12 volt solar power system to a more modern and professional 24 volt system. Was going to give us some serious upgrades and bring our system up from a simple do-it-yourself 12 volt system to something that conformed to code and used higher-end equipment.

Many of our neighbors have really spanky 24 volt and 48 volt professionally installed systems and I have been suffering from a bit of envy over the years. Then our closest friends out here got hit by lightening and lost their very expensive 48 volt inverter and charger system. Cost more than $4000 to replace. That's when I realized that I could probably afford to pay the cost of a bigger system once... but not twice.

So we've altered our plans and we're sticking with 12 volts for the foreseeable future to make use of all the many, many inexpensive solutions available for the 12 volt world. The moment you step up to 24 or 48 volts things start getting really expensive.

So I've been adding and upgrading to our system and I think I've been able to realize about 90% of the gains with less than 1/3 of the costs by sticking with 12 volts.


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## Guest (Feb 23, 2011)

Jim-mi said:


> Thats super fine and dandy to have unlimited fuel (gas) . . .
> But why run that nice ($$) gen on a nice sunny day . .?!?!



I'm in a really poor location to benefit from solar panels .


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## Guest (Feb 23, 2011)

With a battery bank that is properly sized does anyone know if there is a way to determine approximately how many hours the generator would have to run daily , every other day ect. ? It seems to me the larger the battery bank , the less the generator would have to run . How can I determine where the law of diminishing returns come into play when sizing the battery bank ? How much is the life of the battery bank affected by the charge rate ? I've always heard a slow charge was better for batteries than a fast charge . At a slower charge rate I'd assume the generator would have to run more . Lots of things to try to figure out . I wonder if I'm trying to reinvent the wheel since I'm pretty sure all this has already been figured out by someone .


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## Guest (Feb 23, 2011)

If I decide a system is at all feasible I will be lowering my electricity usage as much as is reasonably possible without going primitive .


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## Jim-mi (May 15, 2002)

>>>IF< solar panels can not be used at your site. . . .then sure that $$ can be spent to go with a really good set of bats.. . . .
(bats . .good / better / best )
The bigger the bank (with a proper charger) yes you would cut down the time to run the gen........ Depends on how much your "load" is.


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## wy_white_wolf (Oct 14, 2004)

Depth of Discharge (DoD) has more effect on battery life than rate of charge.



> Cycles vs Life
> A battery "cycle" is one complete discharge and recharge cycle. It is usually considered to be discharging from 100% to 20%, and then back to 100%. However, there are often ratings for other depth of discharge cycles, the most common ones are 10%, 20%, and 50%. You have to be careful when looking at ratings that list how many cycles a battery is rated for unless it also states how far down it is being discharged. For example, one of the widely advertised telephone type (float service) batteries have been advertised as having a 20-year life. If you look at the fine print, it has that rating only at 5% DOD - it is much less when used in an application where they are cycled deeper on a regular basis. Those same batteries are rated at less than 5 years if cycled to 50%. For example, most golf cart batteries are rated for about 550 cycles to 50% discharge - which equates to about 2 years.
> 
> Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor. Also, there is an upper limit - a battery that is continually cycled 5% or less will usually not last as long as one cycled down 10%. This happens because at very shallow cycles, the Lead Dioxide tends to build up in clumps on the the positive plates rather in an even film. The graph above shows how lifespan is affected by depth of discharge. The chart is for a Concorde Lifeline battery, but all lead-acid batteries will be similar in the shape of the curve, although the number of cycles will vary.
> ...


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## mightybooboo (Feb 10, 2004)

WV Hillbilly said:


> I'm in a really poor location to benefit from solar panels .


If its your house thats in a bad spot just move the panels to a sunny area and build a power shed with batts and inverter,etc.Then run the 120 power to the house.

If youre solid trees or a valley,then ignore this idea,LOL!


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## davel745 (Feb 2, 2009)

Here in Pennsboro, WV, we see the sun about half the time the rest is cloudy. I agree with WV Hillbilly Solar isn&#8217;t too practical here. But I do like his approach to the electric problem. I too thought of something like that. The drawback I found is that to keep expensive batteries properly charged and balanced, is a very technical and time consuming challenge. 

The batteries only last about half of the time you think they will. And they are expensive. You need a charge controller and a few other do dads and they are expensive. Not to mention the generator. If you run the whole house off the batteries you will only get a few days off a charge.

I would get a natural gas generator which has a liquid cooled slow speed motor (1800 RPM) sized to power the house. A 20kw unit will run most homes. There life expectancy is about 30,000 hours. Almost 3 and Â½ years at 24/7 of prime power.

You could easily double the time by running it for 12 hours a day.

This is what I am thinking of.

Dave


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## Jim-mi (May 15, 2002)

You need good instrumentation to tell you where your at with that 'good' bank of batteries. . . . . . .and the willingness to faithfully check your meters......
You would in a short amount of time develop a 'routine' for when to run the genny to top up the bats.

It is no big deal.........


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## wy_white_wolf (Oct 14, 2004)

Jim-mi said:


> You need good instrumentation to tell you where your at with that 'good' bank of batteries. . . . . . .and the willingness to faithfully check your meters......
> You would in a short amount of time develop a 'routine' for when to run the genny to top up the bats.
> 
> It is no big deal.........


I'd do all I could to take the "human factor" out of charging the batteries. An inverter/charger with auto-start feature for the genny would solve most of that and take much of the guess work out of when/how much to charge them. Simply set it so when the bank drops to a specific voltage it'll start the genny.

Now a routine for checking battery water levels and equalizing them I would keep. That would also be a good time to change the oil and do any other preventive maintenance the genny might need.


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## Ky-Jeeper (Sep 5, 2010)

What all do you run with N.G. ? If it was unlimited even your A.C. could be free, and also power your car with compressed N.G.

Your electrical needs will be minimal, just buy two smaller generators that are liquid cooled, and alternate run times between them. I wish I had your problem. Good luck.


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## Guest (Feb 24, 2011)

I use natural gas for heat , cooking , water heating & the clothes dryer . I have an electric central air conditioner as I can't find anything in natural gas under 5 tons . I now have a 3 ton unit & a 2 or 2 1/2 ton unit would probably be plenty . I have also checked into one of the cng home stations to compress gas for a cng vehicle & they say you can't do that with wellhead gas but I'm not so sure I believe that .
I wanted the generator to come on automatically when the batteries reached a certain state of discharge . I'm wide open to any & all ideas & the more heads the better so keep your thoughts & ideas coming . I need & appreciate all the input I can get .


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## Darren (May 10, 2002)

"I have also checked into one of the cng home stations to compress gas for a cng vehicle & they say you can't do that with wellhead gas but I'm not so sure I believe that."

Can you elaborate on that? I had one problem with water in the gas this winter when it froze before the separator. That was simply a problem with the way the gas company piped the bypass around the separator. Once I thawed it out, I had gas again. Besides that I know there are several gases that come out of a well that get stripped before the rest of the stuff gets sold to consumers. Locally a fellow has been running his own vehicles from well head gas.

Who did you contact for a compressor?


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## Guest (Feb 24, 2011)

I'm sure the information I got was from google searches I did a while back . It has been a few months but unless memory fails , the company I found that sold the home stations had them priced at about 5 K & I know they said on their website that you couldn't use wellhead gas . I'm pretty sure they didn't elaborate on their reasons for saying that . I assume the person you know that is doing this has one of the home compressors ? Can you find out from him where he got his compressor , how much he paid for it & if he has had any problems ?


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## Darren (May 10, 2002)

He did not buy one of the home compressors. From talking to his son, he has a multistage compressor. I think he used a surplus unit.


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## TnAndy (Sep 15, 2005)

WV Hillbilly said:


> I wanted the generator to come on automatically when the batteries reached a certain state of discharge .


Easily done. 

Get an Outback GV series inverter with the gen start option. When battery voltage drops to a pre-set level ( and you can select that ), auto starts the generator, and tops off the batteries.

A single inverter can give you up to 3600w @120v, and you can gang them together in pairs to double the wattage and give you 240v AC output ( I have a pair of 2500w inverters in 240v configuration ) up to 14.4kw (4 inverters)

Set the battery level to 15-20% DOD, and a good set of batteries will last a LONG time. Look a at DOD chart on batteries, and you'll see the number of cycles only going to 80% versus taking it down to 50% is a LOT more cycles.

AND with a decent sized generator, you can put a HUGE battery bank if you want. Solar and wind, you have to kinda size the bank to the amount of anticipated recharging ability.....whereas with a generator, you can usually have a lot of capacity, so this isn't as much of a concern.


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## Jim-mi (May 15, 2002)

Andy put in better words than I did.
One of my installs is a 15k generator with a Ford liquid cooled industrial engine . . .pumping into a bank of Shurrette 2-KS-33PS. This is fed by a quad set of Outbacks using the AGS.
A while back I had to go out to the site and back off the charging rates . . .too much charge......and ???? if the gen is shutting down properly

I am questioning (and others are to) the Outback AGS system . . .it can malfunction..........

So thats why I say you must have good instrumentation and know how to read it..............


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## Darren (May 10, 2002)

This has been a very informative thread. Living in WV with limited solar indicates I need to buy the best generator I can afford. Much later add batteries in stages as money become available. At least with a generator running on NG, I'll have power if things go dark. I've stockpiled lamp oil and kerosene so I'm good to go with lighting for some time. The generator will be the second priority after converting a vehicle to NG. That will save me money by avoiding buying gasoline when prices are high. Following that the generator is a priority.

Next priority for me would be to buy a rebuild kit to use for the engine years down the road. After that the priority would go to adding a battery setup.


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## Guest (Feb 25, 2011)

Darren , have you considered installing gas lighting ? I assume they would put off quite a bit of heat so you might not want to use them in the hottest part of summer but in cooler weather or if the power is off they would be free lighting . Also , you mentioned converting a vehicle to run on cng . My nephew had a ford Contour that was a factory duel fuel set-up that would run on either gasoline or cng . I would think it might be less expensive to buy a vehicle like this than it would be to convert one .


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## Guest (Feb 25, 2011)

About generators , I assume an 1800 RPM water cooled generator sized just a little larger than necessary to run my home would be the best ? Even though the fuel is free , the larger the generator , the more it's going to cost & more expensive to rebuild & I don't want to use unnecessary gas even if it is free . Your thoughts on this appreciated & also if you know of a particular brand of generator & engine combination that you think would work well for what I want to do .


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## Darren (May 10, 2002)

I wouldn't consider gas lighting. I'm not comfortable with an open flame that's not monitored by a thermocouple and a control valve. If the gas supply is interrupted and then resumes as when my line froze this winter, I don't want gas seeping into the house when the supply restarts. Walking into a room and smelling gas isn't cool especially when the electric power is still on, it's night and your first reaction might be to turn on the lights. I've got three of the old room heaters that don't have the safety setups. I'm working on replacing them. 

I'd love to find one of the duel fuel Fords. One of the issues is that the tanks have, I believe, a fifteen year lifespan similar to other light weight high pressure tanks. Are the code police going to nab you? Probably not. 

I'm looking for a carbureted 3/4 ton F250 with a 300 CID engine. If I can find one in decent shape, that will be the one to convert.


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## Darren (May 10, 2002)

I'm sold on the Lister Petter engine. The smaller units are air cooled. Lister Petters will go, at a minimum, 30,000 hours before needing a rebuild. That means you could run one about four years before rebuilding. Obviously you'd have to shutdown for oil changes. But they are designed to be run continuously. They are diesels so you get a much stronger, longer lived block. When converted you no longer need the fuel injection pump.

The newer models meet all of the EPA regs. But they have to be brought in from England. They've had distributors here for some time. And until the latest round of EPA nonsense, they had factories here too. I've seen the new engines on ebay. They'll cost more than one of the Generacs or similar machines sold for home backup use, but the Lister Petters will long outlast any gasoline engine and many of the diesels. The Lister Petter engined generators are sold under the Hawkpower brand name.


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## Guest (Feb 25, 2011)

I understand your concern about the gas . If my supply is interrupted my regulator shuts off & I have to go reset it before I have gas again . I also wouldn't feel comfortable leaving the lights unattended . The ones I have seen have a mantle like a coleman lantern & give off a lot of light . I'll check out the engine you mentioned .


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## Darren (May 10, 2002)

I have to reset mine too. I happened to forget about the heater in one of the buildings. It was still on when I reset the regulator. Another thing to keep in mind is that for folks getting gas from a wellhead or collection line, the gas doesn't have the strong smell that most folks recognize. The odorant gets added farther down the line.


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## Tobster (Feb 24, 2009)

Newbie here . . . a couple of you guys mentioned using multiple inverters. When you are using multiple inverters, are you splitting the output from your batteries to different inverters. Say you have 16 batteries and 4 inverters, are you sending power from 4 batteries to each inverter? Or, are you sending the output from the inverters to a breaker box and spitting it at the breaker? Is there a limit to how many inverters you can add to your system? Your multiple inverters are a product of growth to your system over time? Thanks


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## TnAndy (Sep 15, 2005)

The battery bank is ALL the batteries you have connected together to form a bank. You then draw from the whole bank and feed your inverter(s).

The output from the invert(s) goes to an AC breaker(s), the same as grid line power would feed your main breaker in a normal panel.

In the case of off grid inverters, most of them I'm familiar with are 120v ( whereas most grid tie inverters already come 240v set up, to feed back to the grid ). So to get true 240v volt, dual phase power, you have to put in a pair of them, along with some kind of "brain" device so one inverter sends power out ( or in one direction )1/60th of a second, and the next 1/60th ( 60 cycle AC ), the other inverter does it.

It's called a 'master/slave' arrangement. You can't simply wire in two 120v inverters, because you just get 120v that way, not 240.

You could add on later, but my guess is most systems are set up with at least a pair initially.....and if you expanded, adding another pair.

Don't know about the limit of the number of pair, other than with Outback equipment, where I believe the limit is 2 pair (4 inverters).....since that is all the HUB ( which is the "brain" thing ) will accept.

*In this photo of my setup, you can see the following:
*
Far right ( white box ) is a 175amp double pole DC breaker that serves as a fuse and disconnect between the battery bank ( which is located directly below, out of photo ) and the inverters. One pole of each side of this dual breaker feeds one inverter.

The inverters are the black boxes arranged horizontally, in the middle, connected directly to the DC breaker box. These are Outback GTFX2524 inverters.....2500w 120v AC output(ea) @ 24v DC input.

The AC output side is the silver colored box ( says "Flexware" ) on it. Right now, that contains 2 main breakers.....one feeds the grid ( this is a grid tie system, with battery backup )....if the grid power goes down, the inverters automatically sense that, and the contact in the inverters open to quit feeding the grid. Another set of contact close, and power from the system is diverted to that second main breaker in the Flexware box. That sends power to a transfer switch and subpanel in my house, allowing me to have power to the circuits I selected as "critical" needs ( refrigeration, lights, etc ).

The small, black box on the side of the Flexware box is the Outback HUB....the brain of the whole system that co-ordinates the input of the charge controllers, the temperature of the batteries, the output of the inverters, and so on. Those small green wires are sensor inputs from the various components in the system.


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## TnAndy (Sep 15, 2005)

Long as I'm at it, here is the input side.....from the PV arrays.....which is looking to the left side of the AC output photo.

Power from the arrays ( 2 at present ) comes into a 2 pole, 60amp disconnect, using one fuse, or pole, for each + feed from an array ( Says "24v DC feed from PV panels"). 

Then each pole of that feeds one of two 60amp Outback charge controllers ( East and West array)

The charge controller outputs then feed to a 100amp SqD subpanel, tucked under the Flexware AC panel. Each charge controller output feeds to a 60amp single pole breaker in that box. SquareD is kinda unique, in that their SQ series breakers, which are normally AC, can also be used (UL listed), in DC systems up to 48v. The also make LARGE single pole breakers....up to 80amp (that I know of)....which is quite handy for large, single pole outputs like this.

The output from that DC panel feeds the battery bank ( still located below at floor level ).











Also, in the DC panel is a 15amp breaker that feeds back to the Tracker supply box ( which has another automotive type fuse in it ) and sends power back up to the tracker actuators on the arrays.

The arrays are located right above the greenhouse, one end of which is the room where this gear for the solar is housed.


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## Tobster (Feb 24, 2009)

TnAndy, thanks for the explanation along with a description of your setup. You do a good job explaining things and making it understandable for us newbies. The photos help a lot, plus they are just plain fun to look at and enjoy.


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## Jim-mi (May 15, 2002)

Yes I know of systems with 12 & 16 Outback inverters like TnAndy has pictured above.
But these systems are three phase . . . . .I am not going to give lessons on installation of that much of a system....


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## Guest (Feb 26, 2011)

I have read that it's important to keep the batteries in an area that maintains a temperature that's not too hot or cold . Would it be safe to use a closet in my home if I vented it outside ? I have a closet I could seal pretty tight & I could run a vent pipe outside .


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## TnAndy (Sep 15, 2005)

Tobster said:


> TnAndy, thanks for the explanation along with a description of your setup. You do a good job explaining things and making it understandable for us newbies. The photos help a lot, plus they are just plain fun to look at and enjoy.


Thanks....It's the ex-shop-teacher in me.....it sneaks back out from time to time....


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## trkarl (Dec 15, 2009)

If you are wanting 240v in an off grid inverter Magnum Energy makes them such as the MS-PAE 120/240V Series Inverter/Charger of the Xantrex XW Series inverters like the XW 6048. 

Or you can do what I did and use a step up transformer like the Outback PSX 240 auto transformer and a 120v inverter.

My system is completely off grid because when I began building it we were not allowed to grid tie. Anyways it consists of a Sunny Island 5048U inverter which is wired to the PSX 240. Then I wired a 10/4 Generator cord to the PSX 240.

I wired transfer switches to the circuits in my house. I plug the PSX 240 into the transfer switches and can choose between grid or off grid power.

On sunny days I run most everything off solar. When it is cloudy I run the fridge and chest freezer off the system only. The fridge and chest freezer run 24/7 off the system. That is one of the rules I follow. This way I know for sure that they can run continuously during a major grid down event.


















I can run my central ac off the system and both my well pumps. I have even ran the ac off the batteries all night one July just to see what would happen. They were discharged to about 50% according to a s.g. reading.
Also the battery monitor showed a 256 amp/hr draw off the batteries that night.


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## mightybooboo (Feb 10, 2004)

trkarl,What are your system specs,panels and batteries? Looks like you're making some good power.


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## trkarl (Dec 15, 2009)

mightybooboo said:


> trkarl,What are your system specs,panels and batteries? Looks like you're making some good power.



Large array: 12 BPSX3200 200 watt panels wired 3 strings of 4 panels
Outback combiner box and midnite solar 10 amp breakers.
4 awg cable from array to charge controller in garage. Approx 70'
Delta lightning arrestor in combiner box. Does it really work? I hope it is never tested.

Small array: 2 BP 585 and 4 BP 590 panels wired one series string.
Medium array: 6 BPSX175 NQ panels wired 2 strings of three into the same combiner as the small array.

This makes one complete array.

Mixing panels this way only works correctly as long as the specs of the strings are as close to identical as possible.
One string of the BPSX175 panels has almost the exact same output in amps and volts as the string of the 590/585 panels.
8 awg cable from arrays to garage charge controller.

Total wattage all together 3980.

Inverter SMA Sunny Island 5048u 5KW 48v This inverter totally rocks!! Huge surge capability plus a generous overload capability.
(SW4048. 4000 watts 48v. For a spare)

Charge controllers:
Outback FlexMax 80 controlling the big array.
Outback MX60 controlling the other arrays.

Planning on a pair of Midnite Classic controllers once they become widely available and cheaper and the bugs are worked out.
http://www.midnitesolar.com/product...ctCat_ID=21&productCatName=Charge Controllers

Outback PSX240 transformer steps the 120 output of the inverter up to 240.
2 Reliance 10 circuit 30 amp transfer switches.
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200321029_200321029

Generator cord wired into the transformer in order to plug into the transfer switches.
This was done for redundancy so I can use either the inverter or generator to plug into the transfer switch if there is a problem with the inverter. The genny can also be plugged into the inverter to supplement it and/or charge the batteries.

Midnite solar mini dc disconnect w/ 250 amp breaker.
http://www.midnitesolar.com/product...tCatName=Mini - DC Disconnect&productCat_ID=8
This is where the batteries, charge controllers, and inverter are all connected.









Trimetric 2020 battery monitor.

Battery life saver 48v desufator. Backwoodssolar.com tested it and says it works. Others say it voodoo.
http://www.batterylifesaver.com/products/products.htm

Surrette 6cs17ps batteries in 48v configuration.
http://surrette.com/pdf/6CS17P.pdf

The most I have ever made in one day was 23 kwhs. This is because I was home that day and was able to constantly load the system as the batteries charged. I could make more everyday but I would have to increase the dod of the batteries which I don't want to do unless I have no choice.

My dod of the batteries averages around 13% per night. Sometimes more but usually that or less.

Off grid systems are highly inefficient because if you don't use the power during the day you lose it where as any extra power in a grid tied system is pumped back into the grid.

It is kind of fun when DW goes away for the weekend to a conference to pull the mains and see how I am able to cope with no grid for a couple of days. Brings power consumption and use into a whole new perspective.


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## Jim-mi (May 15, 2002)

Very nice system . . . . . . .

But you forgot one very "optional" thing . . . .

The price range
(strickly up to you--yes or no)

I know the prices of all that good stuff......BUT . .I'll let you decide if you care to publish.......

I guess my point is that some folks seem to think that "Hey I got the harbor freight special---now I can go off grid." (and power everything) Or that the whopping sum of a couple thousand is going to "get me off grid"

If you want the good stuff like TnAndy and trkral have shown here then you have got to be realist about the price tag for good equipment . . . . . . . . . . . . . .


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## TnAndy (Sep 15, 2005)

I like it Trkarl !

Got one of those "voodoo" desufators on mine too.....I figure, like chicken soup, it can't hurt....

Like your Midnite disconnect too....good to see a photo of it. I used the Xantrex one, and it uses lugs down in the breaker, which is hard to gang BIG wires up on.....the stud sticking out the back of the breaker on the Midnite would be a LOT handier to connect to. Always great to actually SEE stuff ! Thanks !


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## trkarl (Dec 15, 2009)

It all depends on what you want in a system. The stuff TnAndy and I have are meant to be used as a PRIMARY power source where the grid is not available. 

Therefore since we depend on electricity then the equipment must be ... well....
reliable and proven so in the field. You can buy a back up genny for the occasional outage for 300 bucks but try running it 24/7 and you get 300 bucks worth out of it. Buy a low rpm diesel meant to be a primary power source and you will pay several thousand but it should/will run for years. 

My battery banks, both made of the same surrettes, a 12v and 48v alone cost 6k. But they should last for 15+ years. 

Here is the 12v system:










However there is now a 200 amp fuse at the + battery terminal. This is an old picture without the fuse. Notice the difference in size between the 6v Trojan T-125 golf cart battery and the surrette. 

The inverter is a ProSine 2.0

Just to buy the proper gauge wire alone was several hundred. Add it all up it probably comes to around 40k. 

Sure the grid is cheaper and I probably could have better spent that money on several cruise vacations or maybe a brand new Lexus but I digress...

Now I just have convince DW we NEED another 3k panels on the roof. She said that will take a lot of convincing LOL.

This brings up another point of advice for people who want to go off grid. When you begin to build a system make sure to begin with the end in mind. In other words make sure it is easily expandable. 

For instance in a 48v system you can add a huge amount of battery capacity in a single string where as a 24v system of the same size would need 2 parallel strings and a 12v system would need 4 parallel strings.

Also cable size becomes a real problem if you anticipate large ac loads. 
100 amps in a 12v system if it was 100% efficient (no system is) would yield 1200 watts of ac power.
100 amps in a 48v system will yield if it was 100% efficient 4800 watts.

To get 4800 watts in a 12v system you would pull 400 amps. Big difference in cable requirements.

What I am trying to say is really think about the system you are wanting to build before just jumping in. That will pay off down the road.


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## TnAndy (Sep 15, 2005)

trkarl said:


> Notice the difference in size between the 6v Trojan T-125 golf cart battery and the surrette.


Yeah....but come on.....to be fair, you would have to show two of the little golf cart batteries (12v ) next to the Surrette.... ahahahahaaaaaaaaa


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## trkarl (Dec 15, 2009)

What's funny is my surrettes are actually pretty small. Look at some of their 2v cells that weigh 300 lbs each. Ha ha ... that is one HUGE battery. 2430 amp/hrs at the 20 hr rate.


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## TnAndy (Sep 15, 2005)

Yeah.....the 2v cells in my Absolytes weigh about 250lb each.


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## trkarl (Dec 15, 2009)

Do you have a pic of the bank so I can get my battery fix for the night?

Maybe some day I'll grow up and get a real battery bank :rock:


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## Jim-mi (May 15, 2002)

If ya get a Lexus . .what do ya have in 5 or 10 years.........??

Your money is far better spent where it is........


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## TnAndy (Sep 15, 2005)

1200amp/hr @ 24v

Each 2v cell has 4 terminals ( 2pos/2neg )

Weighs about 3,000lbs....about to break down the floor of the single axle trailer it's in...and I had two more sets in the truck when I came home from Kansas.


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## trkarl (Dec 15, 2009)

Thanks for the pic!! I do like the buss bar inter connects MUCH better than cables. 

My next bank will probably be these:

http://www.hupsolarone.com/specs.htm

But the way things are going there may not be a country left by the time I am ready to buy. Maybe that's a good excuse to get it real soon and alternate between banks LOL. Problem is convincing DW another 11+ K in batteries is a good investment.


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## TnAndy (Sep 15, 2005)

Yeah, I like the plate connectors too. My original set of Deka L-16's I had cables running everywhere. These connectors are solid copper with some kind of tin/antimony plating on the outside. 

I picked up 3 sets of these from a buddy at a cell phone company in Kansas for basically the price of scrap + going after them.

Two were new, never in service, the last one had been in service about 4 years ( but was very close on specs for new )...probably never been thru more than a couple cycles.


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## mightybooboo (Feb 10, 2004)

Very nice TK!


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## Rootdigger (Jan 26, 2011)

I pre ordered all the components for my hydroelectric system years before i got it built and just ran the generator through to the batts for that time, it was really nifty. I did learn some things. First get a unit that tells the generator to come on when the batts get low so you don't have to think about it and in inverter that shuts down before the batts get too low if there is a problem with the generator. Temporary large draws will drop your batts below where they are in comfort zone...an example, I could be running everything normal and have plenty of energy in the batts for continued normal use if i checked them manually, but turning on a 1000wt heater for 20 minutes when i am in the shower would drop the voltage in the batts down to 21v instantly where 22.8 is where i wanted them to be charged to prevent damage...gen would kick on and no problem. I ran a Honda 5500 watt generator and for normal usage, lights, TV, computer etc, the generator would run for 1 hour twice a day. This charged 12 6v golf cart batteries. They only lasted 5 years, generator charging is rough on them...$1400 every 5 years but the peace and quiet was worth it. I had the batts in a small compartment lined with 6 inch insulation on the dark side of the house that stayed frozen all winter. At the bottom of the compartment i had a reptile heating mat that ran on 95 watts plugged in all the time and never got below 55 degrees in there...oh also, the inverter/brain read the temp compensated voltage for charging, voltage is lower in winter. The one big lesson i learned was remember that you have to service your batteries, I wanted a small space to keep the heat in but when i went to service it was a nightmare.


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