Author Topic: Is this desulfator any good? (Read 20307 times)

gambit1982 · « **on:** January 15, 2007, 07:41:23 PM »

Hi, I saw this desulfator on EBAY. Can anyone tell me if this desulfator is any good? I picked up 6 free golf cart batteries that are heavily sulfated (been sitting for maybe a year or so), and I would like to try and revive them. They are almost 6 years old, so I duno how much life I would get out of them, but since they are free, i might just give it a try and get some experience in the process. When I put a smart charger on the battery, it would not start because teh voltage level was too low, about less than 1 volt. So I connected my solar arrays, about 18 volts @ 25amps directly to the battery. The battery would take the entire 18 volts, but only about 9 amps or so. But after a few minutes teh battery would start to sizzle. I would leave it connected and check the teamperature every 30 minutes or so to make sure it doesn't go past 100 degrees. And honestly, I can see some of the white sulfate vanishing away after so many hours. But I don't want to leave the solar arrays connected for so long becuase the fear of overheating the battery. So I would like to know if this desulfator is any good and would do the job of breaking up the rest of the sulfate? Or should I just hit the batteries with the chrager for a few days and see what happens? 2 of the batteries that I somewhat brought back to life is taking a charge. But the specific gravity in one of the battery would not go up, no matter how long I would charge it. And the temeperature would hit 110 degrees, then I would disconnect the charge. So if anyone know if this desulfator is any good, please let me know. Thanks

STeven

asheets · « **Reply #1 on:** January 15, 2007, 01:03:49 PM »

My preference is to use this one -- http://www.otherpower.com/images/scimages/231/pulsecrg.GIF -- with a 75Watt bulb and a dimmer in parallel with each other, in place of the capacitor.

gambit1982 · « **Reply #2 on:** January 15, 2007, 01:31:32 PM »

Opps, sorry, I was in a rush to post the comment taht I totally forgot to supply the link. Well, here it is. IT's about $30 only. I just bought one of the black & decker charger that has a built in desulfator but it doens't seem to be doing anything. I put a voltmeter on the battery and voltage does not charge. PUt a ammeter inline with it and no amps??? So I'm goign to return it today because I don't think it does anything.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330075993675&ssPageName=MERC_VIC_RCRX_BIN
_IT&refitem=330071774005&itemcount=4&refwidgetloc=closed_view_item&usedrule1=CrossSe
ll_LogicX&refwidgettype=cross_promot_widget

thanks,

Steven

asheets · « **Reply #3 on:** January 15, 2007, 01:35:13 PM »

Looks like a handful of standard components there -- if you search the board, you can probably come up with a circuit diagram and build your own for less than $30 and SH+H.

gambit1982 · « **Reply #4 on:** January 15, 2007, 02:15:05 PM »

Hi Alan, I'm not very good with building electronics. Heck, I can't even interpret the schematic you posted, lol. By any chance, can you break down the diagram and tell me what goes where and what components I need? I see a bunch of diodes looking thing in the diagram, lol. So are we using AC voltage to charge the battery? I thought battery produce dc voltage? If you can help further explain this I would appreciate it. Thanks.

Steven

RP · « **Reply #5 on:** January 15, 2007, 03:04:52 PM »

That unit puts an average of 45ma (0.045 amps) into the battery in tiny little pulses. That's why your meter doesn't show anything.

This device won't really charge anything. I think it might help prevent a good battery from becoming sulfated but I'm not too confident...

gizmo · « **Reply #6 on:** January 15, 2007, 03:14:16 PM »

I may be just an old fuss, but that circuit looks a little dangerous. In many countries the mains voltage is 240vac, but even at 110 the battery terminals would be at mains potential, bare foot and touching a battery terminal would turn you into toast. Maybe a couple of warnings on that circuit diagram would be an idea. Like make sure the battery is isolated and the terminals are protected against accidental contact with curious fingers. I know its common sense, but lack of common sense is what kills people.

A isolation transformer would make it safe.

Glenn

Nando · « **Reply #7 on:** January 15, 2007, 03:14:47 PM »

Stevens:

The circuit you have found is commonly built by many and the parts as you see them are for about 4 to 5 dollars plus the small printed circuit board, the case and wiring.

The circuit may have the mods I suggested many months ago to a group that have been discussing and building them.

For one and for the time you will need to search for parts and assembly, if you are capable, my suggestion is that your time has higher value, just buy it and give it a try.

CAVEAT EMPTOR the circuit works and do good desulfating BUT it takes time, sometimes weeks, the device is good to have it connected when charging the battery to do desulfating during charging to extend the battery life.

The circuit, by what the advertisement reads, seems to have a temperature sensor to reduce the current been used by the Power MosFet.

I used to make them commercially for large battery banks, indeed in different and capacity.

The circuit using capacitors and rectifiers, I do not recommend they may be widow makers and when I used to experiment technically with them, they were quite inferior than the electronic one, requiring about 5 to 15 times longer periods to attain the same results with the same type of currents.

Nando

solarengineer · « **Reply #8 on:** January 15, 2007, 04:47:24 PM »

Hey Nando,

you wouldn't by chance wish to share a schematic would you??

Jamie

badmoonryzn · « **Reply #9 on:** January 15, 2007, 07:43:31 PM »

I have looked over these posts and ask if anyone could or would pass on a drawing of a working desulfator that someone had some time with and was happy with the results, but no one bite. I drew one up after looking over the two in the posts a few weeks ago. I told it to a friend and he drew another. His won due to simplicity and the ability to be adaptable. There are many ideas how these things should work and I'm sure there will be many more. I have limited experience with these devices and that was 25 years ago before the wonderful semiconductors available now. To be honest people seldom get rid of good batteries, but I'm sure there are a few and because of the cost of new ones I think it is worth my time to make sure. These are so many reasons why batteries get pulled out of service, but seldom are they thrown away if there is some life in them.

Most techs know what I know if not more and I can assure you if I thought for a moment I could get some more life out of a set they would never get thrown away. I care about what happens to the people I work for and I can see no reason to have them replace 5000-dollar battery pack without good cause. Without getting in to a protracted contest on the ins and outs over battery rebuilding, desulfating or whatever one calls it to do any good one has to do the testing themselves as it is not an exacting science. The variables are tremendous, you are working with lethal voltages/amperages and at best you might get through it without blowing up a battery or two.

Any time you pulse a battery with high voltage even for a millisecond you stand a chance of causing an internal spark in a hydrogen rich environment. I have blown up a few batteries in my time and while they are not much in explosive power they certainly will fragment the case and cover the immediate area with sulfuric acid. Fortunately there is not much area in a full battery for gas to accumulate or there could be a bigger bang. With all that said if you do not understand the chemistry involved in why batteries work go read how they create electricity it will help one to understand why one is doing what and why it can be an exercise in futility. I'm all for a good deal and there are some batteries out there that can be a good deal if one can get the sulfides off of the plates, but remember it is part of the process in how the battery creates electricity. I will never get involved in using formulas to try to explain the whys and how's, as there are so many variables and it just opens the doors for arguments and nothing gets done.

I was not very good at remembering formulas anyway that is why I bought a programmable HP to remember the hard stuff. I was more a hands on person and enjoyed the freedom to screw up and learn what worked and why. Here is another version of a pulser. Remember the thing could kill you under right circumstances and again the concept is that, a concept. Not proven. I would hope no one would tackle this process without the understanding necessary to be safe. I have batteries from a 911 replacement and I am willing to see what happens understanding this technology is experimental and nowhere have I seen a commercial unit with the power capable of these voltages and amps. After working out the details with *, this design is capable of 60 pulses per second of 10ms each. This is capable of removing the sulfates on the plates, but it might destroy the battery if it has an internal short. It might do it anyway. Make sure you check for heat, as heat will destoy the battery. No loss, but it might blow up and create a hazard. The drawing is in pdf format I hope it is OK in here. Be careful and have fun.

Badmoon

Nando · « **Reply #10 on:** January 15, 2007, 08:08:49 PM »

Jamie:

The common ones are in the public domain, I will try to find one to place in the site.

I am developing one that is a "munster" I mean monster, good for high current batteries and of course uses a lot of power and will have at least 4 ports to charge 4 batteries at the same time, either in series or not connected.

My main problem is lack of TIME !!

Too many items in the fire.

Nando

badmoonryzn · « **Reply #11 on:** January 15, 2007, 08:12:08 PM »

nuts it didn't post. if anyone wants it I can email it to them. I will convert it to a format that posts

moon

Nando · « **Reply #12 on:** January 15, 2007, 08:18:38 PM »

I have uploaded a desulfator_n.gif for those interested

Nando

RP · « **Reply #13 on:** January 15, 2007, 08:51:01 PM »

pdf files can't be displayed in-line here. Anyone can find it by clicking on "User Info" on your post and then getting it from your files.

If you can convert it to a jpg (with no spaces and ending in ".jpg") it'll post just fine.

badmoonryzn · « **Reply #14 on:** January 15, 2007, 09:00:44 PM »

Cool, Thanks Russ! I took me three months just to figure out how to post?

?? I missed the point on pushing the button again. Man I'm gettimg blind and stupid.

Badmoon

windy · « **Reply #15 on:** January 15, 2007, 09:28:33 PM »

Badmoon

I can't tell for sure, but is that a 1 uf 250volt cap in parallel with the .01 uf cap? Are all the caps 250 volt? I might be able to get some golf cart batteries to try to desulfanate and am looking for a simple curcuit to build.

Thanks!

windy

Gordy · « **Reply #16 on:** January 16, 2007, 01:34:32 AM »

Alan,

Do you have a link that tells how and why to use the bulb and dimmer.

Thanks

Gordy

badmoonryzn · « **Reply #17 on:** January 16, 2007, 09:58:34 AM »

Yep it's a one microfarad polarized electrolytic. I hope you get some use out of it because I have not had the time to build the thing myself, so any comments once you try it would be useful. Oh yea, why not to your other question. With any luck one of the design engineers here might look it over and comment too. :-)

moon

asheets · « **Reply #18 on:** January 16, 2007, 11:29:25 AM »

Yea, an isolation transformer would make sense. I've occasionally used one for this, but most of the time I use a remote switch behind a shelter when I turn the thing on.

asheets · « **Reply #19 on:** January 16, 2007, 11:37:04 AM »

No, this is just a modification I came up with. Most of the time, I don't need to change the amperage (which is what the capacitor does). Instead, what I want to do is to either limit the input voltage (which is what the dimmer will do) or limit the circuit wattage (which is what the light bulb does).

The circuit itself is protected (at long range) by a 20amp motor-type circuit breaker, so if the stuff on the plates doesn't break free right away (usually accompanied by a loud snap or a few seconds of extreme buzzing under a full load of electrolyte) then the power is cut off. Once the plates are clean, I turn the voltage down so that I don't boil off the electrolyte or melt the innards -- but even then I don't run this thing for more than 5 minutes at a time.

asheets · « **Reply #20 on:** January 16, 2007, 11:48:00 AM »

120VAC is fed into the diodes (actually, a Whetstone bridge circuit -- you can either by a bridge can or build the bridge out of individual rectifiers) at two points. At the other 2 points, 120VDC is output. The function of the bridge is to take the points of the AC sine wave that are reversed polarity and "flip them over". The output is not pure DC -- it is a pulsing DC at 60 half-waves per second.

There is a lot of debate whether it is the voltage that does the desulfating, or the pulsing DC that does it. If you go out to the message boards that talk about desulfating batteries, you'll read a lot of stuff about fancier desulfators seeking the "resonance" frequency of the battery to do the most efficient job. I'm not to convinced of that myself, but I'm not prepared to argue. I figure that if 60Hz at 120V DC doesn't do the job, then the battery is too far gone to mess with. Plus, my personal guess is that many of the cheaper commercial desulfators on the market are just rehashed inverters that run at 400Hz anyway -- not variable frequency units as they are advertised.

Finally, I would say that if you don't understand the watgas circuit diagram (which is pretty simple as schematics go), you probably shouldn't try building it. I don't want to come off as arrogant or mean, but this literally is a simpler design than a Boy Scout crystal radio -- but much more dangerous if something goes wrong.

ghurd · « **Reply #21 on:** January 16, 2007, 11:54:51 AM »

Picking nits. Just for clarity.

"pulsing DC at 60 half-waves per second".

Maybe that should read 120 half-waves per second?

I 100% agree with you.

G-

asheets · « **Reply #22 on:** January 16, 2007, 01:46:48 PM »

Aren't 555's just the greatest IC ever?

Seriously, though, on this circuit, what is the pulse frequency and voltage?

asheets · « **Reply #23 on:** January 16, 2007, 01:48:42 PM »

(grabs a pencil and starts drawing waves...)

Yep, you're right -- a 60Hz sine wave will yield 120 pulses/second when run through a bridge. Good catch.

asheets · « **Reply #24 on:** January 16, 2007, 01:50:56 PM »

Yea... I agree with one of Badmoon's main points, and it can't be stressed nearly enough.

If you are charging or desulfating batteries, YOU MUST DO SO IN A WELL VENTALATED ENVIRONMENT!!!!

Nando · « **Reply #25 on:** January 16, 2007, 03:54:52 PM »

The frequency is around 1 KHZ and the current pulse around 0.56 anps

The current follows the formula V = L * dI/dT

But when the pulse is fed to the battery it penetrated deeply until finding a hard point (sulfation) presenting a low resistance value which forces the pulse to shorten it fast which is the equivalent of increasing the peak current from about 8 to 15 times depending on the battery conditions.

Nando

alibro · « **Reply #26 on:** January 16, 2007, 05:26:11 PM »

I couldn't be bothered building one from scratch (and don't have the time as my turbine is nearly finished) I have some 90ah sla batteries that need some help so I just ordered one from ebay, total price £17.36 inc postage. I will let you know how I get on

Ali

solarengineer · « **Reply #27 on:** January 16, 2007, 08:11:12 PM »

Many Thanks Nando, greatly appreciated

Jamie

asheets · « **Reply #28 on:** January 17, 2007, 10:24:11 AM »

Now, see... that's a concept I can understand...

elvin1949 · « **Reply #29 on:** January 17, 2007, 06:23:54 PM »

I right clicked it then clicked view file.

IT OPENED

later

elvin

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Author Topic: Is this desulfator any good? (Read 20307 times)