Battery desulfator

Try trickling about 50 volts at a max of 100mA through the battery for a few days.

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    Dave Plowman        dave@davenoise.co.uk           London SW
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snipped-for-privacy@webtv.net (Ken G.) wrote in news:14018-45DF1471-474@storefull-

3235.bay.webtv.net:

Vector makes battery charger/maintainers that desulfate batteries.

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Jim Yanik
jyanik
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So how is it supposed to work? I like to have a car battery around to blast dendrited ni-cads but they usually end up sulphated sitting around too much.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

In theory you can reverse the process by reversing what caused it. So a slow charge for a very long period *might* work. Trouble is most modern chargers don't allow a high enough voltage to produce meaningful current through the battery so you need a bench supply or purpose made job. Or an ancient totally unregulated type where the off load voltage is high.

FWIW it's only worked once for me where a relatively new battery was knackered through leaving the car lights on for three weeks. ;-) A jump start got the car going, but the battery was still totally flat after the

30 mile journey back from the airport. It took a week of high voltage before it would take any real current and start charging. It lasted for a few years after that.

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    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

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"N Cook" wrote in news:ern9h6$4s4$ snipped-for-privacy@inews.gazeta.pl:

If you Google "desulfator" you will find circuits that can be built very inexpensively.You will also find references to how they work.

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Jim Yanik
jyanik
at
kua.net

"Warren Weber" wrote in news:BLCdnaCqwvc3GELYnZ2dnUVZ snipped-for-privacy@bresnan.com:

A POX on the twits who post gif or other binaries along with their replies to threads on this NON-binary newsgroup.

that would be YOU,Warren Weber. KNOCK IT OFF,CEASE,DESIST.

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Jim Yanik
jyanik
at
kua.net

I read that website for a long time and got very confused at all the different stuff there . I would like to buy a desulfator already made that i can plug into the wall .

But do these really work?

I can only recall 1 or 2 replies with actual success stories, and at least 1 of those could have been a situation where the battery was caught just in time so that there was minimal sulfation.

If I have a battery that's been sitting around discharged for a year, will anything help?

Comments?

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Exactly the same interest, if there is a viable answer. As far as i was aware nothing could remove the layer of insulating and insoluble lead (bi)sulpha(i)t(d)e? film other than mechanically scraping the plates

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Hi...

I have no idea whether or not what I experienced was "sulphate" or not; but for what little it may be worth...

Left a garden tractor with a snow blower attached and an almost new battery installed sit for two or three years untouched.

When I finally got back to it it was dead, not a click.

Found one of the battery posts (pos, I think) evenly and completely covered in a flat black "something". Looked like it had been painted.

One of those round battery post wire brushes wouldn't even scratch it.

Using a course file and tons of elbow grease removed it. Then a long charge at 10 amps or so gave me a few starts - but for practical purposes the battery was garbage.

IF that black stuff was indeed sulphate, I can't see anything touching it.

Take care.

Ken

Warren yes the above email works . I see circuit diagrams on that website provided earlier . It is not100% clear and i have no idea where to get the semiconductors & coils .. I want to buy one already made unless the parts are very common . I have a few blow 12V to 120V invertors if those might have those IRF transistor things in them ? .

The batterys i want to start with are all inside those portable jumpstart units . 90% of them are new stock from costco out of salvage return loads . They are new but they wont charge up . Some are very low , some are flat dead . The batterys are black box sealed 12 volt . Unfortunately these have all been stored where it freezes . Each unit has its own charger inside it . I have tried leaving some plugged in for a week with no results .

I thought of ``waking them up`` with a quick good jolt of 24 volts from a big charger .

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Back when the only thing I knew about chargers/batteries was polarity had to be observed I bought a cheap 1 amp trickle charger cause it was all I could afford. IIRC it put out 18volts under light/no load. I "brought back" a couple of batteries with it by leaving it on for a couple of days. I got several more months of use from the batteries in warm weather but they still didn't have enough capacity for cold starting and had to be replaced then.

I've never really looked at the units in question but my experience says theirs probably some merit to them. Question is, do you want to put that kind of money into something that's going to give batteries of suspect usefulness. I have batteries because I want to use them when needed, not screw around with them. I think most people would be better off buying quality batteries and learning to take care of them. Lead acid batteries self-discharge ~1%/day. I'd never mess with a battery that had gone below

10.5volts.

I have a MC with a 9 year old battery in it. Manually charged it in the off season the first 5 years and have been using a Battery Tender the last 4. The BT makes the chore much easier. IMHO it makes a lot more sense to keep a battery healthy than to resurrect a dead one. YMMV

i once tried using baking soda to "clean" the plates...emptied electrolyte, used baking soda, rinsed alot, refilled with electrolyte...it didn't really work...it was a motorcycle battery...i was 15

i now think of the plates as more high tech, only the amount of lead necessary...not like they are solid lead that the surface can be cleaned...imho

Some guys spray paint them to prevent corrosion. Others use grease or felt washers soaked in grease.

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Ken -

Well, that's a different question. What makes you think you want a desulfator? Most battery manufacturers say that desulfators are junk, by the way.

You might start with the FAQ section on this site

In particular scroll down to question 16. Since you have sealed batteries, you can't do everything that is suggested, but it might give you some ideas.

It is worth rummaging around that site - there is a lot of good info. I think it suggests that your idea of "a quick good jolt of 24 volts" might, in fact, be a good answer.

On the other hand, if the battery became discharged and then froze, there is nothing you can do. The case may have cracked, or at least the inner structure is hopelessly deformed.

Good luck.

Bill Jeffrey

I know of few people who used a desulfator. It did the job, but only for a short while. We think the plates inside the batteries took on some permanent damage.

In the end, when we calculated the loss of time, the cost of the device to do the desulfacation, and considering the potential unreliability of the batteries, we came to the conclusion, it is better to buy new batteries, maintain them, and they should last at least 3 to 5 years.

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JANA _____

I have been searching on the net for one that simply plugs into 120 volts for use inside . Most of them i see hook to 12 volts and stay in a vehicle . Some 120 volt ones cost 500$ . I am looking for one around

100$ .

What can anyone say about these .

What makes you think you want a desulfator?

Hi Bill ... to recarge batterys that will do so .

Good info on that website . It sounds like a low % of success . A guy here in town got a desulfator and said it worked well on the new batterys i mentioned . I lost contact with that guy . Its worth a try i think to spend a little & try this .

I wonder how they work with only 2 wires . Dont they require input voltage .

snipped-for-privacy@webtv.net (Ken G.) wrote in news:1640-45E1D534-900@storefull-

3234.bay.webtv.net:

they use the battery's voltage,step it up and generate a short fast-rise pulse.Some are meant to be used in conjunction with a battery charger.

--
Jim Yanik
jyanik
at
kua.net