The Ford Barn

callcoy · 01-05-2012, 01:20 AM

The store bought battery tenders or maintainers do a great job of keeping batteries fully charged without over charging. I have found these, friendly priced for from $21.50 to over $45.00. Does anyone out there have a schematic for one of these units, I would like to see if I could build one. I have a pile of used chargers from phones, printers and etc. that I think would be large enough to maintain a car battery. I have used a number of these to power solenoids and even windshield wiper motors in household applications.

Tom Wesenberg · 01-05-2012, 03:24 AM

If your transformers put out at least 6.7 volts you should be able to use them for a trickle charger/maintainer. Many already put out DC, so all you need to do is put a couple battery clips on the ends. If they put out AC, then you can go to Radio Shack and buy a small full wave rectifier to install on the 2 output wires.

Doug in NJ · 01-05-2012, 10:51 PM

So, how many milliamps should a trickle charger be trickling into the battery?

Doug

Mike V. Florida · 01-05-2012, 11:24 PM

Keep in mind that battery tenders like the one sold by Deltran monitor the battery and provide a charge only when needed, float mode. It is not a "trickle" charger.

If you have a trickle charger you might want to put it on a household timer set for 15-30 minutes a day.

callcoy · 01-05-2012, 11:46 PM

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Thank you Tom for your input, Mike, kind of hits on my concern but Doug really nailed it. I have chargers that convert to a trickle mode, I am looking to build a "Tender" that does not overcharge the battery, but floats. Meaning as the battery loses a little of it's charge it is gently brought up to a full charge condition, then the system shuts down, it doesn't stay on forever.

01-05-2012, 01:20 AM	#1
callcoy Senior Member Join Date: May 2010 Location: Hendersonville TN Posts: 180	Battery Tender Clone The store bought battery tenders or maintainers do a great job of keeping batteries fully charged without over charging. I have found these, friendly priced for from $21.50 to over $45.00. Does anyone out there have a schematic for one of these units, I would like to see if I could build one. I have a pile of used chargers from phones, printers and etc. that I think would be large enough to maintain a car battery. I have used a number of these to power solenoids and even windshield wiper motors in household applications. __________________ Steve - Santa Rosa

01-05-2012, 03:24 AM	#2
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Battery Tender Clone If your transformers put out at least 6.7 volts you should be able to use them for a trickle charger/maintainer. Many already put out DC, so all you need to do is put a couple battery clips on the ends. If they put out AC, then you can go to Radio Shack and buy a small full wave rectifier to install on the 2 output wires.

01-05-2012, 10:51 PM	#3
Doug in NJ Senior Member Join Date: May 2010 Location: Princeton, NJ Posts: 965	Re: Battery Tender Clone So, how many milliamps should a trickle charger be trickling into the battery? Doug __________________ My '31 S/W sedan project:http://31ford.dougbraun.com My restoration diary: http://dougbraun.com/blog

01-05-2012, 11:24 PM	#4
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: Battery Tender Clone Keep in mind that battery tenders like the one sold by Deltran monitor the battery and provide a charge only when needed, float mode. It is not a "trickle" charger. If you have a trickle charger you might want to put it on a household timer set for 15-30 minutes a day. __________________ What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

01-05-2012, 11:46 PM	#5
callcoy Senior Member Join Date: May 2010 Location: Hendersonville TN Posts: 180	Re: Battery Tender Clone Sponsored Links (Register now to hide all advertisements) Thank you Tom for your input, Mike, kind of hits on my concern but Doug really nailed it. I have chargers that convert to a trickle mode, I am looking to build a "Tender" that does not overcharge the battery, but floats. Meaning as the battery loses a little of it's charge it is gently brought up to a full charge condition, then the system shuts down, it doesn't stay on forever. __________________ Steve - Santa Rosa