desulfator

[Mike Gibson]

I am woundering if anybody is using a desulfator? I want to know how it is working out and if it is store bought or homemade.

[Mark Parsons]

Hi Mike,

I was hoping someone would reply to your post that has direct experience with a pulse desulfator. I have been considering and am also looking for advice. Research indicates it is a device of value to keep the batteries in prime condition.

I almost bought this one on e-bay when ordering a diversion water heater load from this vendor.
http://cgi.ebay.ca/500AH-Battery-DESULFATOR-for-SOLAR-WIND-POWER-Systems_W0QQitemZ120114091870QQihZ002QQcategoryZ32 40QQtcZphotoQQcmdZViewItem

If you are looking to salvage old batteries, there are some simple circuits on the Otherpower site. One is as simple as using a capacitor from the mains 120VAC. Definitely a little dangerous if not shielded and a discharge resistor used.

Regards,
Mark

[Mario De Castris]

Hello Mike and Mark,

Welcome Mike and sorry for not answering your post sooner, but the wind is blowing which is good for generating power and the sun is not shining which is good for fishing. Regarding desulfator I've tried 2 or 3 manufactured different units and non of them give me any quick good result, I have a commercial unit that seems to do the job whenever I need to recondition some old or misused batteries that seems to work very well to bring batteries back to life. A long discussion about desulfator was on a few months ago on another board and everybody seemed to think that the store boughtonce are not powerful enough to restore large Renewable Energy batteries. To the best of my knowledge the manufacturer are not allowed to sell powerful enough units because of regulations, so everybody recommends you buy a homemade or make your own, unfortunately I am too cheap to spend $300 on speculation for a homemade and too lazy to build my own to test, so to this date I asked any of my friends or customers that have problem with a lazy cells to bring them over to me and I will rejuvenate them with my commercial units.

Mario

[Greg Eckard]

Mark ;

Have you heard of a chemical call EDTA? Someone said that this would desulfate an old battery.

[Mario De Castris]

Hello Greg,

I would recommend using EDTA only as a last resort for old batteries and if you have had a lot of experience with it.

Mario

[Mark Parsons]

Looks like good discussion and info at this site.
http://p198.ezboard.com/bleadacidbatterydesulfation

[Mike Gibson]

I also have heard that the commerical ones are not as good as the homemade. This sight list the parts for P channel FETs and N channel FETs with several other gadgets to add to the desulfator to make them more reliable.
http://www.flex.com/~kalepa/desulf.htm
I was at a small (real small) radio shack yesterday and the had most all the parts. I didn't get any,i was on my way to work.

[Stewart Corman]

I had spent a considerable time looking at both the patents and DIY sites before purchasing a unit (ebay $20 shipped) ... mine is a small Schumacher for just doing car batteries, not the big banks of batteries you guys are talking about..

That said, building a DIY is not trivial and most cookbook solutions don't work out quite the way they are supposed to ( unless you are a EE and know what you are really looking at ...I am an ME)

here is a link I saved besides the last one posted:
http://enpub.fulton.asu.edu/nsfreu/Gorlando/BatteryReport.htm


There should be nothing wrong with a store bought Schumacher or Vector which are the two big names and amp size is NOT the criteria !!

I have done extensive bench testing on mine and I can say that the limited advertising literature they give you is total BS !!

All function at high frequency (3.26MHz) to break up the large crystals formed from slow discharge ...mine goes 6, 4 or 2 amp at either 12 or 6 v

If you read the patent ...a low amp slow charge for 48 hrs is required.

Trick in a large bank is to determine which single battery needs help, or else do all of them sequentially.

The biggest problem is determining what the existing capacity of any battery really is under load conditions???

I have a mental design for building a tester data logging into a PC, but is low priority ( wanted it to test NiMH batteries for digicam) ..so I cheated:
I have a 3 bulb, 12v lighting fixture for a camping trailer, with a multiposition switch.... with all lights on in parallel, R= 1ohm ie 12 amp load

Remember that I am recalling numbers from memory as nothing was written down.

When I connect to a "dead" battery that has been conventionally charged (10 amp w/ amp meter) to >12v I see how long to get the lights to "dim" ( voltage under load >=10v)
For one battery ..it was less than 5 minutes
recharge same process ..no diff

BTW, sometimes the "Smart Charge" circuit does not allow the discharged battery to charge at all. Keep trying until it clicks on. Their micro looks at a dV/dT threshold

So I put the high tech desufator charger on 6 amp setting and it clicks off in about 15 minutes. Didn't take the charge much and bulbs lasted about 10 minutes.
tried again ..same thing
then I put it on 2 amp setting
charged for about 2 hrs ...bulbs lasted about an hour
charged at 2 amps again ...charge took about 4 hours
bulbs probably lasted 2 hours

third time ...ran overnight until showed "fully charged"
bulbs ran 9+ hours and were still going strong when I quit ( wasn't going to wait around ) ...now conventional charger works for several hours until meter showed typical <1 amp charge rate ...QED

Mark, please comment on my testing technique or chime in if you have any criticism of my conclusion.

Stew Corman from sunny Endicott

BTW ...I wouldn't add any "chemical" to a battery to try and improve it's charging characteristics ..it it really worked, then everyone would do it ... not how the chemistry works ( did I mention that I am a ChE too? )

[Mark Parsons]

Thank you Mario and Stew for the testimonials. Confirms a lot of anecdotal evidence that a pulse desulfator works.

I believe it can also provide some preventative medicine for a battery bank. Prevent the initial build-up of lead sulfate reducing the battery's effectiveness. A small pulse device only uses a few milliamps of average current. Does this small continuous power drain offset any sulfation losses over time? Use it monthly for a couple of days? Quarterly for a week? Less? More?

It seems to me that this technology has existed long enough that some lab should have done some public domain research to experiment and quantify the phenomena so that most efficient devices and techniques can be designed and integrated into all chargers to keep the millions and millions (billions?) of lead acid batteries lasting and performing at peak as long as possible. I know, I know, not in the best interests of the battery manufacturers' sales departments... :mad:
For those living off the grid and using battery banks, losing almost 20% in prime condition batteries is enough without adding further potential sulfation losses.

Anyone aware of any scientific studies and / or published results?

Regards,
Mark

[Stewart Corman]

Mark,

Anyone aware of any scientific studies and / or published results?


did a quick google and came up with these (which may or maynot be relevant):
http://www.sandia.gov/pv/docs/PDF/caploss.pdf
http://www.ipenz.org.nz/ipenz/publications/transactions/Transactions98/emch/2wilkinson.PDF

you'd think that Consumer Reports would jump on this, but I can't find any ref there ...I googled it

Stew

[Dan Aube]

Hi guys not on this site very often but take a look at this desulphater http://www.duoregen.com I've been using it for roughly 6 years with great success.

[Mike Gibson]

I looked for a price but couldn't find one. Have to call a distributor i guess.

[Timothy Wayland]

I have six 2 volt 1320ah hawker cells which are wired in series to give 12 volts. It is the battery pack I use to supply a mastervolt 2000/12 inverter. Well the batteries are in Sulfate City, and the only 12 volt de-sulfators I can find on ebay or anywhere else seem to be designed for car or other much smaller batteries.
What should I be looking for,can anyone help?

[Chris Olson]

Timothy, chances are that you already own the most effective battery desulfator ever invented - called a battery charger.

Sulfation is a normal condition in a battery, and happens as it discharges. The battery charger reverses the condition. If a battery has been allowed to remain in a discharged state for a long period of time an the sulfation has hardened, then the only thing that will fix it is an equalization charge.

You should refer to your battery manufacturer's recommendations on equalization, but typically it will involve raising the voltage to 2.75 volts per cell, or 16.5 volts for a 12 volt series string. If they are badly sulfated it make take several equalization charges to correct the condition.

If the battery is worn out the sludge formed by material that comes off the plates will collect in the sump and short the plates, rendering the battery useless. If the battery is still serviceable and has enough sump room left so the plates don't get shorted, it will come back to life.

A note on the pulse-type desulfators being mentioned here (although this thread goes back to 2007) - I have yet to see any conclusive proof that they actually work. In theory, on very small batteries with light plates it might. But when you're talking about 1300 ah cells, forget it. The plates in those cells are more than likely about 3/16" thick. If the lead sulfate on the plates is no longer in an amorphous state they're going to have be boiled at 2.75 VPC for many hours to correct it.
--
Chris