making battery charger?

WordUpOnLCDs · 29th December 2005, 07:25 AM

How would I go about charging Koyo My 12v BAttery with my 18VDC @ 5.5VA hobby transformer? Is it possible without alot of work I havent really done this kind of stuff before. I also have some different power supplys Ive gathered over the eyars such as 12VDC @ 500ma, 5.0DC solid line over dotted line 2.0A?, 11.2VDC @20ma, and a bunch more laying around, if its any help. Thnx

AndrewT · 30th December 2005, 07:37 AM

Hi,
you need to achieve 4 targets with your charger.

1. set a current limit to avoid overheating and gassing, your sealed battery requires a different charging strategy from old technology lead acid.

2. set a voltage limit to avoid overcharging and gassing. I think sealed require about 13.8volts.

3. establish the VA required to meet the above for quick charge (not less than 10hours) any quicker risks damaging the battery.

4. find info on temperature compensation for the voltage limit related to battery temperature.

A nice option would be automatic change over to trickle charge when full charge and/or highest temperature is achieved.

Another nice option is reverse polarity protection.

WordUpOnLCDs · 30th December 2005, 09:02 AM

is it advisable to use an adapter I have that is 12vdc @ 500ma to charge it? I mean is it safe?

AndrewT · 30th December 2005, 05:30 PM

Hi,
12Vdc will not charge a 12V battery. You need more than 12V to overcome the battery voltage plus the resistive losses in the charging circuit.

Stocker · 30th December 2005, 08:40 PM

batteryuniversity.com

WordUpOnLCDs · 31st December 2005, 07:30 AM

would an automotive float charger work to recharge my battery or does that only maintain it? like these i found on ebay http://cgi.ebay.com/TWO-12V-AUTOMATI...QQcmdZViewItem

29th December 2005, 07:25 AM	#1
WordUpOnLCDs diyAudio Member Join Date: Dec 2005 Location: Mary-Land	making battery charger? How would I go about charging Koyo My 12v BAttery with my 18VDC @ 5.5VA hobby transformer? Is it possible without alot of work I havent really done this kind of stuff before. I also have some different power supplys Ive gathered over the eyars such as 12VDC @ 500ma, 5.0DC solid line over dotted line 2.0A?, 11.2VDC @20ma, and a bunch more laying around, if its any help. Thnx

30th December 2005, 08:40 PM	#5
Stocker diyAudio Member Join Date: Dec 2003 Location: Austin	batteryuniversity.com __________________ Jesus loves you.

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30th December 2005, 07:37 AM	#2
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, you need to achieve 4 targets with your charger. 1. set a current limit to avoid overheating and gassing, your sealed battery requires a different charging strategy from old technology lead acid. 2. set a voltage limit to avoid overcharging and gassing. I think sealed require about 13.8volts. 3. establish the VA required to meet the above for quick charge (not less than 10hours) any quicker risks damaging the battery. 4. find info on temperature compensation for the voltage limit related to battery temperature. A nice option would be automatic change over to trickle charge when full charge and/or highest temperature is achieved. Another nice option is reverse polarity protection.

30th December 2005, 09:02 AM	#3
WordUpOnLCDs diyAudio Member Join Date: Dec 2005 Location: Mary-Land	is it advisable to use an adapter I have that is 12vdc @ 500ma to charge it? I mean is it safe?

30th December 2005, 05:30 PM	#4
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, 12Vdc will not charge a 12V battery. You need more than 12V to overcome the battery voltage plus the resistive losses in the charging circuit.

31st December 2005, 07:30 AM	#6
WordUpOnLCDs diyAudio Member Join Date: Dec 2005 Location: Mary-Land	would an automotive float charger work to recharge my battery or does that only maintain it? like these i found on ebay http://cgi.ebay.com/TWO-12V-AUTOMATI...QQcmdZViewItem