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Old Chopper has been workin' on makin' a desulfator, Im up to mark 7 so far and they seem to actually work well, I have 3 "out there" on beta test :p

The idea is to generate short sharp high voltage (around 50 volts) high current (greater than 30 Amps) pulses that are fed to the battery to "shock" the sulfate crystals off the lead plates.

Here is a screen shot of the open circuit voltage of mark 7 [Image: OpenCircuitVoltage.bmp] as you can see, theres around 50 odd volts (peak) there.

And now connected to a fairly crappy and old 12 volt 9AH gel cell, [Image: VoltageAcrossBattery.bmp] the voltage has dropped but thats ok, it means its working. Its the CURRENT peak we are interested in now.

I used a 0.22 Ohm 5 Watt resistor (lowest value I could easilly find)  in series and measured the voltage accross it with the CRO [Image: CurrentToBattery.bmp] It was at a peak reading of 11 volts, that means 50 AMPS of peak current! The peak voltage and peak current will drop as the battery improves.

If anyone is interested in more, or wants to have a crack at making one, let me know.  Aus_flag Smoking
Confused2 arrhhhhh ya giving away our money making idea. Make big dollars from dead batterys to later buy big 1kw uhf amps with.

LOL, that little battery seems to be coming back to life. I'll do an update tomorrow.

Aus_flag Smoking
Cool, Im very interested in how the little bugger goes. I have 2 down in the Skunkworks working away again on test. Im trying to find a way of telling when the battery has got as good as it can be after the process. I also found a coupla thermistors to try and make Mark 8 version with "feedback" so it can adjust itself to suit the condition of the battery. More improvements are in the pipeline, like a "computer controlled" version using either a PIC 16F84 or an Arduino (because I have some of each of them and need an excuse to play with 'em)(Google that stuff  Toothy12)

Last time I got bored around this time 'o the year, I built a "computer controlled" Christmas tree star, thing still works, I'll video it later and bung it up on youtube, it uses a PIC chip and a dunny load of different coloured LED's mounted in an old plastic star thing.
I WAS going to make a string 'o Christmas lights that go to music with my Arduino, but I (as usual) got sidetracked.  Tears
See what happens when Nerds get bored  Tears Ow well havin an early nite tonite, buggered meself up muckin about in the shed.  Smoking Cya Ahh NERDS.
12PM Update: I notice the led is off now while the battery charger is still running.

Led will light for a second while connecting it back up though.

Battery is at 12v with no leads at all connected.

I think from memory I tried to charge that one another time but it never did shit and stayed at 5v.

No smoke yet  Smoking
Its good that the battery is sitting at 12 volts. I gather thats the really bad looking battery?

The desulfator needs a really good and solid connection to the battery terminal. I have found that as I desulfate some batteries, I get some corrosion appearing on one terminal, check to see if thats happening.

The light should be on and thne device should sing a bit as well, if you cant hear it, a test is to bung an AM radio, like what we used to listen to 4GG on near it, you should hear the pulses from the device on the radio when its tuned off station.

No smoke is good too! I gather the desulfator didnt get too hot eh?
Just went up and had a look.

Yeah it's on that shitty old looking battery.

The light is on, but not as bright I thinks it was originally.

Relay kicks on when the terminals go back on. Seems all good.

Quick voltage reading shows 12.40v now which is up more, but slowly goes down while watching for 30 seconds or more.

Ow well, it's above it's stubborn 5volts

Warm all across the whole battery side like it's cooking away OK

Yep sounds good to me, I just checked on mine as well, still chugging along and charging up. Might have to wait a few days, maybe weeks, but its doing the job so far!  Smoking
101212 desul update

2pm, 10/12/12 check up.
Looks to me like the desulfator is working.

The bubbles are ok, but be careful as they are hydrogen and oxygen bubbles, and you know what happens if ya have a spark near that lot!

I have a couple of suggestions: bung a car tail light bulb in series with that batttery charger to limit the current the battery can take. a 21 watt light bulb (the average tail light bulb) will allow around 2 amps and will be a bit safer on the battery whilst its being desulfated, I am using a charger with around 1 amp output on one battery and 1/2 amp on another. The desulfator only draws around 1/10th of that. Better still if you can use one of the bulbs out of a car that are around 10 watts.

Patience grasshopper the desulfator works at around 1/2 kilo worth of battery per day, and you cant hurt it by leaving the desulfator on it too long, it'll just flatten it eventually unless to trickle charge it as well.

If one part of the battery is quite a bit warmer than another, it can mean a shorted cell by dendrites, load up the battery with a headlight bulb on high and low beams together and discharge it down to 10.5 volts. After that, trickle charge it back up with the desulfator connected.

Book1 Icon_thumright Smoking Cya
PROJECT: Lead Acid Battery Desulfator 12/12/12/ Update

All 6 cells...ow well...I cover it in the video  Smoking
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