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dom44
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Joined: 26/04/2017
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Posted: 10:04pm 30 Jul 2019

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I have been playing around with battery desulfators for a while now with limited successes but i noticed that when you use AC power in series with a capacitor and diode it begins to work then reaches a sticking point, where the battery voltage stops climbing back up.
But if you lift one of the terminals and cause it to spark a few times all of a sudden the voltage climbs up again so i came up with the idea of using a strobe circuit where a capacitor discharges into a transformer from high voltage

to lower voltage high current into the battery so far looks good i am testing on a battery that had zero volts and is now at 4.6v will keep you posted.

mackoffgrid

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Joined: 13/03/2017
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Posted: 10:57pm 30 Jul 2019

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Interesting.

I tried the AC-Cap-Diode method and got nowhere.

Look forward to seeing your results.

Cheers
Andrew

Chopperp

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Posted: 11:01pm 30 Jul 2019

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Hi dom44,

First post. Welcome to the Forum.

Please tell me that you haven't got the negative of the rectified mains connected to the battery negative as shown in the diagram. (Unless of course, you are using an isolating transformer for the 220 VAC).

You need to have electrical isolation between the two.

Brian

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dom44
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Posted: 12:15am 31 Jul 2019

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my mistake you are right should not be connected

Warpspeed
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Posted: 12:30am 31 Jul 2019

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Welcome to the Forum dom44

I have not had a great deal of success with desulphators magically resurrecting completely dead batteries, probably because there are many reasons batteries die, besides just sulphation.

These kinds of circuits seem to work best with batteries that are still fairly healthy, but need to be kept alive for extended periods while just sitting in storage essentially doing nothing.

Cheers, �Tony.

Chopperp

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Posted: 02:49am 31 Jul 2019

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dom44 said my mistake you are right should not be connected

I was hoping it might have been a "Line-o" (as opposed to a type-o)

(Smiley faces not working yet).

ChopperP

Chopperp

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Posted: 02:50am 31 Jul 2019

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Edit Smiley faces are working

ChopperP

BenandAmber
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Posted: 03:42am 31 Jul 2019

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I have messed around with these with hundreds of batteries

When your battery will hold 12 volts but there's no capacity like when you put it in a car it just clicks

These are the type of batteries I've had really good luck with

almost everyone comes back

But if it won't at least hold voltage to begin with it's just hit and mess mostly Miss

So in other words if it's sulfated and that's the only problem then you'll probably have good luck

be warned i am good parrot but Dumber than a box of rocks

BenandAmber
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Posted: 03:46am 31 Jul 2019

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Nicad batteries are just hit and miss had okay luck with them though

I have also heard you can Flash them with your welder if they have a shorted circuit and sometimes it will burn the short out

Welcome to the forum

be warned i am good parrot but Dumber than a box of rocks

dom44
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Posted: 04:41am 31 Jul 2019

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I have repaired an ODYSSEY battery with a desulphator first time i got full voltage could run a 300w sander for 5 mins after pulsing would run for 20 mins i am still pulsing it right now it shows that it can do some good on some battery's but depends how far gone the battery is.

BenandAmber
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Posted: 05:13am 31 Jul 2019

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Yep it definitely works but if you want your success to be almost 100% get the ones that are already holding voltage

Almost every battery I've ever hooked up has been improved just some more than others

be warned i am good parrot but Dumber than a box of rocks

BenandAmber
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Posted: 04:06am 04 Aug 2019

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This book was from when you charged your battery up to 15.6 volts

And batteries lasted a lot longer

Any battery that is lead acid and not sealed should go to 15.6 volt before taking off the charger for a full charge

Or that's the opinion I have any way

be warned i am good parrot but Dumber than a box of rocks

renewableMark

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Posted: 10:35pm 04 Aug 2019

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Batteries were probably made a lot better back then mate. (1927)
Thicker plates, higher up from the bottom to avoid sediment shorting with them etc.

Modern batteries are made to a price and usually aren't designed to last long.

BUT some are, my forklift traction battery is expected to give 20 years in a solar application and 6-10 in a forklift that chews the power all day every day.

Modern chargers bring them to absorb voltage and vary the amps to keep them there for a specified time (mine get 2 hours @ 57.6v) Then an equalise once a month for 2 hours @64v.

If you ask 10 people how best to charge a battery you'll probably get 10 different answers.
Edited 2019-08-05 08:36 by renewableMark

Cheers Caveman Mark
Off grid eastern Melb

BenandAmber
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Posted: 01:23am 05 Aug 2019

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You're right mark those forklift batteries intrigue me love to get my hands on a set of them

I am thinking of putting a 48 volt alternator on my bus I have plenty of room for it

It would be nice to be able to charge the battery Bank while I'm going down the road

Kind of sucks that I'm only going to be able to put a little over three thousand watts worth the solar on the roof

be warned i am good parrot but Dumber than a box of rocks

BenandAmber
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Posted: 06:45pm 09 Aug 2019

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Put new starting batteries in the bus the other day decided to try to recover a couple of the three that came out of it

Third day At A little over amp and a half maybe another day or two to go
Edited 2019-08-10 04:46 by BenandAmber

be warned i am good parrot but Dumber than a box of rocks

Solar Mike
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Posted: 11:24pm 09 Aug 2019

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Best of luck there Ben, trying to revive old dead batteries is akin to flogging a near dead horse; you may achieve some sort of result, but it will be very short term.

Cheers
Mike

BenandAmber
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Posted: 01:27am 10 Aug 2019

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I would have to agree with you solar Mike

But if the battery is not damaged other than sulfated

this method seems to work really well matter of fact the first one that I ever did just died the other day

I used it on my Onan generator for two or three years and then my buddy. Staregazer used it in his Mustang 4 about a year-and-a-half

When the battery was giving to me it would take a charge and read almost full Voltage but when you tried to crank your engine over it would just click

I dumped all of the acid out of it and made a solution Epsom salt you know the kind that smells like old lady

that's the only kind I can find at the time

I don't think that the Epsom salt is such a good idea

Now I just leave the battery acid in there and top it off if necessary

When Jacob got married he went on vacation afterwards and was gone for a month

the Mustang has always ran down a battery after a few days of not running it

so the reason it died was the Mustang killed it
I haven't lost hope I just haven't had a chance to put it on the capacitance battery charger yet

it may still have a few good years in it lol
just checked it and it's still reading 12 volts

this batteries resting voltage has always been over 13 volts since I put the Epsom salt in there

it seems to have a little bit less capacity then a normal battery of this size maybe 75%

I think that's something to do with the Epsom salt I've had similar results every time I've used it

With all this said I still agree with you
It's not worth doing unless your battery is just sulfated any other problem it's not going to fix

Edited 2019-08-10 11:37 by BenandAmber

be warned i am good parrot but Dumber than a box of rocks

BenandAmber
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Posted: 01:56am 10 Aug 2019

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Quick list of what I've learned

When you take the Caps off of a battery and there is a oily substance floating
On top of any of the cells not worth messing with

When you take a flashlight and look closely down in all of the cells if any of them look badly deformed or weird in any way not worth messing with

If you look in all the cells and the water is completely clear and there is a whitish Grey coating all over the plates

And your standing voltage after it has been setting for at least 2 hours is over 12 volts you have a chance the higher the voltage the better the chance

This is just my opinion and the experience I have had

be warned i am good parrot but Dumber than a box of rocks

kentfielddude
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Joined: 09/05/2019
Location: United States
Posts: 89

Posted: 08:27pm 21 Aug 2019

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Saw this circuit on youtube. Seems pretty simple to build.

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