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lentildude
Joined: 23 Aug 2008
Posts: 4
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 Posted: Wed Sep 16, 2009 11:35 am Post subject: wanted; cheap deep cycle batteries for small solar project |
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I am after some cheap deep cycle batteries for a standalone solar system I am scrounging together. I finally secured some old solar panels, now need batteries. Looking at about 200 -300 AH and 24v. I am in the penrith area.
any leads appreciated |
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kimbal
Joined: 15 Apr 2009
Posts: 37
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| Posted: Wed Sep 16, 2009 2:22 pm Post subject: Re: wanted; cheap deep cycle batteries for small solar proje |
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| lentildude wrote: |
I am after some cheap deep cycle batteries for a standalone solar system I am scrounging together. I finally secured some old solar panels, now need batteries. Looking at about 200 -300 AH and 24v. I am in the penrith area.
any leads appreciated |
I have an Electronics trade background, with technical experience working for LATRONICS Sunpower in Caloundra, Queensland; testing and repairing inverters for solar installations.
As for batteries i suggest looking into these alternatives >
Try and source old truck batteries from a WRECKER yard.
In Melbourne a Truck wrecker in Boronia was charging about $20 for good battery from a TRUCK. "Good" does not mean it has 12 volts across the terminals. It must be able to start the truck and have a suitable water-acid balance. < [ To do this take a Hydrometer with you, when testing them as well as a DC LOAD Meter.You may still be able to get the old style 'rubber bulb with glass tube and measuring float' Hydrometer from AUTO shops.
If you don't have a DC load meter, make one from a multimeter current range, a current shunt, and a low resistance DC load set for say 100 amps at least. The load for 12 volts @ 100 amps could be made from 12 x 12 volt / 100 watt flood lights wired in parrallel, to pull 100 or so amps at 12 volts being almost 1200 watts of short term power from one truck battery..]
You will need to know what voltage your Solar Inverter will be. If it is 48 volts input you will need 4x 12 volt batteries all of the same charging capacity. Some solar cells have a very wide NO LOAD Open circuit voltage and can damage your inverter, if a suitable regulator is not installed between the solar panels and the batteries which run the inverter.
As fior inverter size that depends on what you want to run and the capacity size of your solar panels. I like to run an inverter of no mnore than 60-70% of its output to allow for real hot days and spike overloads.
( But then I over-engineer everything, as if the army was using it.)
Try Telstra --- yards for BIG Lead-Acid batteries, as they MAY have old 2 volt lead acid cells going cheap from old telephone exchanges yards. Also some electroplaters may still have old ones available - but I doubt it nowdays.
You will need a number of them to make up your inverter input voltage, but in a way this is better if you can source enough of them in good condition. Build a small weatherproof enclosure outside for housing the cells, to eliminate any hydrogen gas build up on discharge.
Expect about 10-15 years from your SOLAR panels, if looked after from new. As for the Batteries, try 5-8 years with new cells and maybe 2-3 with older cells. Use INOX to decrystalize your batteries after establishing they are worth recycling. Inox is available at CAR AUTO Shops and hardware stores like Bunnings but costa about $10 dollars for a small bottle of about 100 ml. You will want 2 bottles for each truck battery; one if it is a car battery - just read the labels first.
A third solution is to make your own batteries from scratch and this can be done if you have access to a fair workshop and the correct electrochemistry knowledge to make the spongy lead for the plates, or whatever is required.
Alternative batteries are, you could build are an air battery or a EARTH cell which are in some ways superior to conventional Lead Acid, but you will need lots of Mercury and/or heaps of Lead - both materials are now banned under RoHS law and difficult to get in any quanity.
Go for the air battery, or salt water batteries / Aluminium cells as materials are easy to source, lithium - air cells which have up to 10 times more power than any car battery and in theory some can be made at home.
Heaps of general info on the web on such cells. Some of these do not have to be recharged but will require maintenance to last for some time. Some examples of the concepts are here.
You might have to do your own research on making cells as BIG batteries are expensive and hard to get construction details on.
I know of a mecury earth battery used during WW2 made from a large lead plate ( ABOUT 3 FEET SQUARE AND ABOUT A QUARTER OF AN INCH THICK ) needing a FEW Litres of mercury and I tihnk a zinc or iron plate as well was needed of the same size as the lead plate. It was burried in the ground and could supply HUNDREDS of amps continually at 2 volts for months at a time. I have a design for it somewhere. It never needed charging and it would last for YEARS without any maintenance.
A number of these earth cells would fix all your power problems but the mercury will be your real issue.
Some links on alternative batteries are here >
h t t p : // w w w . miniscience.com/projects/airbattery/
h t t p : // w w w . exo.net/~pauld/activities/AlAirBattery/alairbattery.html
h t t p : // w w w . treehugger.com/files/2009/05/lithium-air-battery-research-breakthrough.php
Best of luck ! |
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lentildude
Joined: 23 Aug 2008
Posts: 4
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| Posted: Fri Sep 18, 2009 11:03 am Post subject: batts |
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thanks for all that info , I didnt think of wrecker yards for truck batteries, but probably hard to get 4 identical batteries from a wrecker. I am looking for telstra data centres or someplace discarding 2v cells but no luck so far, I dont have any engineering contacts in telstra thus posted my message on gumtree.
I already have an inverter and my solar panels are 40w panels but since they have been used for 18 years they were guaranteed and tested to produce 33w min.
I would love a good mppt charger but they are costly and the cheap ones on ebay are from china who only accept paypal so still looking locally for a bargain mppt controller too like the Bluesky device.
Back to the battery search. . . |
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Rich000
Joined: 15 Oct 2009
Posts: 12
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| Posted: Thu Oct 29, 2009 2:01 am Post subject: |
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| Some underground mining companies use electric powered vehicles. This way I got a huge pile of NiCads 2v 200Ahr as --- and they all work fine. They will last me for many years. Just track down a mining sparky, he'll tell you how they dispose of the old batteries and how you may be able to get some. Dont expect to pay much if anything. They have to pay to dispose of them so you are doing them a favour. |
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hunterr
Joined: 02 Nov 2009
Posts: 1
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| Posted: Mon Nov 02, 2009 10:09 pm Post subject: got batteries - in victoria |
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did you get what you were after?
I've got a stack - hunterr@gmail.com |
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