Author Topic: 12 volt dry charged  (Read 2005 times)

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tljones

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12 volt dry charged
« on: February 07, 2007, 01:22:01 AM »
Hello everyone!!!! I am a newbie, but this question seemed specific enough that this seemed much more the place to put it. I have spent at least 20 hours over the past month reading into these subjects and a lot of that on old posts on this site, but this is my first question.


I am an on grid resident in the frozen and very wind north of SD. I recently built a home on a very windy site, and am in the middle of my research and data gathering on what size I will build my turbine.  Also gathering information on an array of subjects. I have three kids and a wife who are very addicted to on demand power, and my home is 100% electric. I have gone a long long way into the efficiency side of things, and have a ways to go yet, but with the wind resource I have it is an obvious resource. I know however that I am never going all the way off the grid. Also SD is not a net metering state.


So I have found a source of a large quantity of surplus batteries that appear to have never been used. The following is a description.


BATTERY STORAGE, LEAD ACID, DRY CHARGED, 12 VOLT, SIDE POST, 74 SIZE, 60 AMP HOUR


I think I know what I am looking at. I am presuming that the dry charged means they have been stored without acid ever having been added. The side post tells me that they are not deep cycle, but the numebr of these available even if I was only using half of the amp hours would go though an inverter for a nice number of kilowatt hours of storage.


Is my math right???


12 volts X 60 amp/hours=.720 WATTS* 50% charge reserve =.31KWH per battery. If I had 50 of them I would have a 15.5kwh useful battery.


Two questions.



  1. Tell the idiot what he is missing....
  2. If I were to get these batteries at some reasonable cost, would there be a better way of hooking them into a usable system to be created than leaving them as a large 12 volt bank???


BTW, I am the idiot.....


Thanks!!!!

« Last Edit: February 07, 2007, 01:22:01 AM by (unknown) »

craig110

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Re: 12 volt dry charged
« Reply #1 on: February 06, 2007, 07:50:58 PM »
Welcome to the fun world of alternate power!


I am not familiar with dry charge batteries, but one thing to consider when looking at the price of those 50 batteries is the effort needed and costs to connect them.  I use 2/0 wire to connect my batteries, and since I only have 8 batteries I didn't get a huge bolt cutter but rather just sawed through the cable to make each segment.  That takes a while for each one, and I sure wouldn't want to do that for 50 batteries.  So, if you don't already have one I'd suggest adding a hundred dollars or so to the comparative price of the batteries for a large bolt cutter.  Also, factor in the price of the connection components (wire and terminal lugs) when comparing your battery options.  60AH batteries are pretty small, so you'll have to buy more connection components than for an equivalently sized bank of larger batteries.  (For example, my 8 batteries are Trojan T-105s with 220AH each, giving 2/3rds the aggregate size of those 50 batteries for only 1/6th the number of interconnect components.)  It might sound like a minor thing, but a couple of bucks per battery starts to add up when you're talking about 50 of them!


I'll defer to others as to whether dry charge batteries are suitable for turbine use, though.

« Last Edit: February 06, 2007, 07:50:58 PM by craig110 »

RogerAS

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Re: 12 volt dry charged
« Reply #2 on: February 06, 2007, 07:55:54 PM »
tljones,


Reasonable cost? Depends on how long they live before you have to replace them, and what you'll replace them with at some point when these die. If these are much cheaper than 6V golf carts then even a couple years use might be acceptable, if they price is right.


Cables and terminal connectors need to work with future batteries.


If the batteries come with electrolyte or do you have to buy that?


I'd go with a 48V system for the DC.


Lead acid flooded batteries aren't near as effective in real cold weather. They will be less so the colder they get.


I used to live in Lemmon, SD up in Perkins County so I know about your wind and cold. For those of you that don't know the wind in SD can be awe inspiring at times, especially at -35° F. What part are you in? I'd consider searching this site for postings about direct heating with wind, as our host DanB is doing.


You might consider a grid tie solution as well.


Just tryin' to help

« Last Edit: February 06, 2007, 07:55:54 PM by RogerAS »

craig110

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Re: 12 volt dry charged
« Reply #3 on: February 06, 2007, 07:58:37 PM »
Oh, sorry, forgot one point.  It is generally accepted that unless you are planning on wiring your house to directly use 12v appliances, a higher voltage system is easier to deal with since higher voltage equals lower amperage for a given wattage level, and that translates into being able to use thinner wires.  48v systems are typically the high end since the NEC has, IIRC, special requirements for home systems designed for 50v (nominal) or higher.  If you do get those 50 dry charge batteries, consider wiring them in 12 parallel strings of 4 batteries each to get 48v.  You'll end up not being able to use 2 batteries, but given all the other cost savings I believe you'd come out ahead this way.
« Last Edit: February 06, 2007, 07:58:37 PM by craig110 »

tljones

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Re: 12 volt dry charged
« Reply #4 on: February 06, 2007, 08:42:24 PM »
I am in the NE corner of SD, and while there are colder places, there aint a lot of them. I am currently in the process of putting my small test turbine together that I am going to use for heat in my garage. From there I figure I can translate my productioon out into real data for designing a bigger one.


The actual lot of these batteries is actually quite a bit bigger than the 50, but it seemed like a nice round number. I guess I am trying to figure out if I can get them for 7 or 8 bucks apiece how I can go wrong?????  Seems to me that a lot of alternative energy is finding a way to make good use of something that no one else has a use for.....


I have a chop saw and such so I am not really to shook about the shelves and connections. I farmed for 8 years before I got pissed and left so I have pretty good skills at rigging stuff up once I understand the rules.  trying to see if there are unexpected pitfalls I am missing. For things such as controllers and electronics I am more than willing to pay retail, because I just dont understand them. But I think I know just enough about batteries to be dangerous....:)


Tom

« Last Edit: February 06, 2007, 08:42:24 PM by tljones »

Flux

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Re: 12 volt dry charged
« Reply #5 on: February 07, 2007, 12:40:49 AM »
From the description they are military starter batteries.


Dry charged batteries have a shelf life from a few months to a few years depending on the manufacturing process and how well they have been stored.


Unless you can find out how old they are, you are taking a chance. Even so they will have a short life for your duty.


If they are not too old, are in reasonable condition and come cheap you could be on a winner.Otherwise it is very much a gamble.


Flux

« Last Edit: February 07, 2007, 12:40:49 AM by Flux »

vawtsup

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Re: 12 volt dry charged
« Reply #6 on: February 07, 2007, 08:15:45 PM »
"Also SD is not a net metering state."


I know this is only the smallest part of your post but you might want to see if your utility company is on this list.


Public Utility Regulatory Policies Act of 1978 (PURPA) as Applicable to the Energy Policy Act of 2005 (EPACT 2005) - List of Covered Electric Utilities


http://www.oe.energy.gov/DocumentsandMedia/PURPA_2006_final.pdf


I know many utilities have resisted this law ,mine included, and have lost.


Worth checking any.


Ron M

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« Last Edit: February 07, 2007, 08:15:45 PM by vawtsup »

dbcollen

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Re: 12 volt dry charged
« Reply #7 on: February 23, 2007, 09:31:17 PM »
Dry charged batteries have basically an infinite storage lifetime !!!!IF!!!! the cells were dry nitrogen purged and sealed. the positive plates are made of lead dioxide (PbO2) the negative plates are pure sponge lead. If the cells were exposed to moisture then both plates would be oxidized (PbO2). This is not a problem either, but it takes more work to activate the batteries. To activate an oxidized dry charged battery, fill with electrolyte and charge for several days at 2.45 volts per cell (14.7v), but do not exceed 125 deg F. Charging will deoxidize the negative plate.

« Last Edit: February 23, 2007, 09:31:17 PM by dbcollen »