off grid energy ... need info/links

[hnash53]

This post has more to do with off grid energy production than building, but here goes.

I am buying a large deep cycle battery bank ... 16 12volt batteries with a total of 1920 amphours @ 12 volts or 960 amphours @ 24 volts.  I plan to use a combination of solar and wind, with a supplemental generator.  I read that there are various ways to wire the batteries, in series and in parallel, to increase capacity and/or increase voltage.  If the bank is wired for 24 volt, do I have to use 24 volt solar panels and 24 volt wind turbines?  Additionally, can I charge a 24 volt battery bank with a 12 DC generator?

If these questions are beyond the purpose of this forum, can anyone provide GOOD links, GOOD books, or a GOOD quality alternative energy forum where I can get some of these answers?

You guys are always so great.  Thanks.

[MountainDon]

What kind of batteries are those you're considering buying? You called them deep cycle, that's good but not the whole story. Is the 1920 amp-hours at the 20 hr rate?

Don't know much about wind generated power other than there are some differences in the equipment that controla the power going to the batteries. (Haven't enough dependable wind here for me to have bothered much with learning about it.)

You wire the [highlight]solar panels[/highlight] and get the power to the batteries via a [highlight]charge controller[/highlight]. A really good controller like the Outback MX60A can accept virtually any input voltage you can throw at it. It has a max input of something like 150 VDC but in many cases you should limit the input voltage to 48, maybe 72, to allow for overvoltages that may occur during cold temperatures. (Solar cells perform better in the cold; their open circuit voltage can go quite high.) If you overvolt the MX60 it has the ability to remenber what voltage hit it, and if it's outside the parameters set by Outback, no warranty.

The MX60 controllers output voltage is also user configurable so you can match it to virtually any battery pack you can cobble together. With the batteries you described go with a nominal 24 volt system, don't mess with 12 VDC.

Question for you re the generator you mentioned. A 12 VDC output? The normal thing is to use a 120 VAC output gen and then convert that power down to whatever the battery pack is wired for; 12, 24, 48 volts. A really good power inverter can be had with a battery charger built in. Or you can choose to go a separate charger route. I believe Iota  makes chargers for 24 volts, but may be special order. And re the inverter be sure you buy one that can be stacked with another identical unit so you can increase the output when you outgrow your estimation.

And as far as that goes, how'd you come up with 1920 amphours worth of battery. If you did it right and way over estimated your power use, great! You almost always want more power down the road.

[hnash53]

Each is 134 amphours @ 20 hr rate.

If I wire the batteries to be a 24 volt system, can I still charge it with 12V solar and 12V wind and 12V DC generator?

[MountainDon]

Each is 134 amphours @ 20 hr rate.

If I wire the batteries to be a 24 volt system, can I still charge it with 12V solar and 12V wind and 12V DC generator?

I added to the first post as well as writing this one..

By type of battery I mean more like , are they really designed for long life off grid power use?  Most really good batteries meant for serious long lived power systems are based on 6 volt or even better 2 volt cells, there are also some 4 volt units. They have very hi amp rates and you just wire up enough in series only to make your voltage. Placing batteries in a number of parallel circuits to obtain the required amp hour capacity looks good on paper. The theory is correct, but the batteries themselves never read the theory book. Over time small differences in cells make themselves apparent and can cause problems that result in you having less capacity than you began with. As well the battery life may be shortened.

[MountainDon]

If I wire the batteries to be a 24 volt system, can I still charge it with 12V solar and 12V wind and 12V DC generator?

With the right charge controller from the solar, yes. Not sure about wind power at all. Generator see post above. Also re the 12 VDC gen you metion; what's it's output in terms of amps at 12 VDC or watts at 12 VDC??

[MountainDon]

can anyone provide GOOD links,

Best people I ever talked to are found at        www.theSolar.biz

[glenn-k]

I'm running everything 24v inverting to 110 and 220.  I hear the Outback is a good regulator - running higher voltage cuts wire sizes then cut it down to 24v for charge with the Outback.  I already had a Trace regulator and the Bergey comes with one.

I have the Bergey xl1 and their site has some info about it.
http://www.bergey.com/
Bergey Windpower Co., the worlds leading supplier of small wind turbines


I have 2 trace 4024 older sine wave inverters stacked for 220.  Mountain Don is right - You usually want more.

I have 12 L16 batteries - would like 16.

Usually you will series them to 24v then parallel those groups for more storage.

DIY    http://www.scoraigwind.com/
Hugh Piggott - Scoraig Wind Electric

http://www.fieldlines.com/
the Otherpower.com Discussion Board  Make your electricity from scratch!

http://www.redrok.com/main.htm
Red Rock Energy Heliostats

http://www.homepower.com/magazine/index.cfm

http://www.builditsolar.com/

http://rmrc.org/rustpower.html

http://www.poormansguides.com/

[littlegirlgo]

The best book I have read - and Ive read at least nine so far - on solar is "Photovoltaics: Design and Installation Manual". Its very detailed with many diagrams. Its published by Solar Energy International. I got a copy from Amazon for $16.00.

[Amanda_931]

Rex Ewing can be cutesey, but pretty easy to figure.

Here's the link for design and installation manual--Not no sixteen bucks--and that was about the low price I found.

http://www.amazon.com/Photovoltaics-Installation-Solar-Energy-International/dp/0865715203

Rex Ewing--might be better for a first book.  He's made a bunch of mistakes, and learned from others', his wife is good at setting him straight.

I have the earlier edition of this book (the one you see if you click on "search inside":

http://www.amazon.com/Power-Nature-Second-Alternative-Homeowners/dp/0965809897/ref=reader_req_dp/002-4170165-9831267