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kivdenn
Nobel Prize Winner
Uganda
535 Posts |
 Posted - May 28 2007 : 03:30:06 AM
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| Thanks Pal but I used a Transformer of 30VAC,40 Amps and the transformer is very hot, I dont know what is making it hot. Also the output current is very low yet I want a minimum of 25 AMps. Thanks |
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kivdenn
Nobel Prize Winner
Uganda
535 Posts |
Posted - May 28 2007 : 03:35:02 AM
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| I used a 30VAC 40 Amps out put transformer but is geting too hot I dont know what is causing this.Dennis |
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pebe
Nobel Prize Winner
United Kingdom
1078 Posts |
Posted - May 28 2007 : 08:29:11 AM
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There is no way you can get 25A out of this charger - Q1 is only rated at 4A max. If you want that sort of current then you would best go to a switched mode supply. Why would you want to charge a battery at 25A, anyway?
30V is way too much for the supply. You would need a rethink of the component values R4 to R8 and some form of current limiting would be required.
Regarding the transformer overheating. Are you sure the primary of your transformer matches your mains supply? |
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kivdenn
Nobel Prize Winner
Uganda
535 Posts |
Posted - May 28 2007 : 11:42:17 AM
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| I have two 530AH 12V batteries connected in series thats why I need the 25Amps and the 30Volts is the transformer output. When I disconnect the circuitry the transformer cools down. Do you have access to any of the switched mode supply battery charger circuits. Please avail me some. Thanks, Dennis. |
Edited by - kivdenn on May 28 2007 11:44:28 AM |
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pebe
Nobel Prize Winner
United Kingdom
1078 Posts |
Posted - May 29 2007 : 2:17:57 PM
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I’ve had no luck looking for switch mode circuits for the current you want. There’s probably not much demand by ‘do it yourself’ people. But here is a site with useful information on charging, if it’s of any use to you.
http://www.batteryuniversity.com/partone-13.htm
You will see they recommend a 36hour charge for large batteries like yours. So perhaps you could get by with 15A. It might then be possible to modify the published circuit.
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darchua1
New Member
1 Posts |
Posted - Nov 26 2007 : 08:58:13 AM
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Hi all,I'm Darren. Regarding one of the earlier post where there was a link: http://www.vt52.com/diy/myprojects/other/charger/charger.htm
I'm thinking of building the 1.2A version charger. The battery I'm charging is a 6V 4Ah Lead Battery. From the equations provided, I should be getting a max current of 0.4A and a resistance(R) of 1.5ohms. From this values, I would be expecting power of 0.24W at my resistor(R). The resistor I'm using for R is only 0.25W. Would that burn the resistor? By the way, do I need to bother about the power rating of the other resistors too, expecially the variable resistor? If all the resistors were rated to be 0.25W, would that be ok? I look forward to the reply. Thanks :) |
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DexterLB
New Member
Bulgaria
1 Posts |
Posted - Jul 28 2009 : 02:12:04 AM
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Hello.
I saw [url=http://www.aaroncake.net/CIRCUITS/charger2.asp]this charger circuit[/url]. It seems pretty good to me, so I want to make it.
But I have a question: :)
I want to charge a 12V/7Ah sealed lead-acid battery. But it's max charging current is 1.8A, and it's optimal charging current is 700mA. How can I lower the output current? |
Humans are stupid |
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hellion
Apprentece
Nepal
5 Posts |
Posted - Apr 02 2010 : 11:39:09 PM
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I was using my 600 VA UPS as a inverter for my 12v 200ampere battery but its not working these days
what can i do to make it work |
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pebe
Nobel Prize Winner
United Kingdom
1078 Posts |
Posted - Apr 03 2010 : 04:31:01 AM
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If you know how it works, then try to repair it.
If not, buy another. |
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Regarding the connection of the charger circuit.
