My new pulser/pulse-charger.

[mael]

I started right off the bat with a typos! The ""newest"" pulser ................

ZZZzzzZZZzzzZZZzzz

[mael]

I had to replace the transformer as it overheated. I am using a trans from a very small welder. It puts out around 40 V and I think it can handle 40 A for a while. Seeing it in the new pulser makes me think I've now found a close match to my ideal image of a transformer for a pulser.

The poor transistor is holding. When it pulses, I can notice the lights using the same socket dimming. - I mean it is working as I wanted it to.

A 75 A/h battery sporting cells which wouldn't raise the float in the SG meter was connected about 24 hours ago to my new pulser. Well that's not quite right - it raised the float on half of the cells, but was off the scale.

The pulse is around three every two seconds. I'd like to increase this, but I don't think this transistor would appreciate it so I'll hold on with this at its slow pulse until I can get something meatier.

I did twelve hours or-so with the pulse alone. At the end of this time the SG was in the region of 1100. I was not terribly impressed.

Then I connected a charger which put perhaps a couple of A into the battery as it was being pulsed. I ran the charger through an inductor to stop the pulse from getting smoothed-out by the cap on its output.

- And the difference is startling. So approaching twelve hours with a 20 - 30 A pulse and a trickle charge has brought the SG to the 1200 mark.*

The more I go on the more it seems as if the desulphating is more effective in a given time if the amperage is high.

I shall continue with this report around the same time tomorrow.

probably.

* The Amperage may well be up to 40 judging by the current drain I can observe. - It's like someone's running an automatic washing machine when the lights keep dimming each time it changes direction. - But it's not quite so noticable of course.

[mael]

It certainly appears as if a slow trickle charge of maybe a few per-cent of C in addition to pulsing with a sharp snap is the most effective method of rejuvenating the batteries I have experimented on thus far.

Regular charging makes little differencene on a sulphated battery, but a long float charge of several months works.

Just a sharp pulse is also somewhat slow. But a slow pulse which charges a bit seems to be effective.

[SeaMonkey]

Mael,

Your observations and conclusions are very much consistent with others who've performed the same kinds of trials. Well done!

The trickle charger used may even be one of the very small ones that outputs half-wave rectified pulses of only 1 Ampere or less.

The very short (sharp) pulses are most effective at breaking down the sulfation into active plate materials; and the wide (longer) pulses are more effective for charging the battery. So a pulser operating at 1 KHz to 5 KHz producing very sharp and narrow pulses, combined with a trickle charger to accomplish re-charging the battery as newly recovered material becomes available at the plates, is the ideal solution.

There are occasions when the newly 'rejuvenated' battery's performance is less than stellar (weaker than hoped for); but in those cases discharge the battery under heavy load until the measured voltage reads 10 Volts, then repeat the pulsing/charging and test it again. It may take several cycles to restore it back to its maximum state of recovery, but you should see improvement with each cycling until it levels off.

It is truly amazing to see how you methodically overcome the various obstacles as you progress with creativity and ingenuity. As a famous American test pilot would have said, you've definitely "got the right stuff!"

I'll upload some circuit schematics into my project folder shortly.

Harbor Freight has a sale underway presently and their very nice Digital Multimeters are going for $1.99 - These are very easy to 'convert' into a high current Digital Ammeter which is capable of reading up to 200 Amperes (or even 2000 Amperes if needed) by use of a home-made external shunt. They're 7 function meters which measure the usual stuff and Transistor Current Gain (beta) as well. A real bargain, and you can purchase up to 8 at once with coupon.

Making a 'Load Tester' for 12 Volt batteries is quite easy.

I don't suppose you have any of the Harbor Freight outlets on Amami do you Mael?

[mael]

[mael]

[mael]

[mael]

[mael]

[mael]

[mael]

[mael]

I added three LEDs in series with the gate-supply to take it to one Volt. From there I can adjust it via a variable resistor up to about 15 V (overkill). This meant I could adjust the current in the pulses. Obviously necessary with something so powerful.

There's now a 20 milliOhm reistor in series with the rectified output of the transformer to the cap bank. This is really so I can easily connect a meter and get an idea of what power is going through the system.

I adjusted the pulse to be approx 2 Hz because I thought the transistor array and related parts could manage it.

There is a 10 mFd cap in series with a variable resistor across the relay coil which gives me a broader pulse if I want one.

The purpose of this pulser is to test high-current pulses to see how effective they are at desulphating.

Well it's been a god 12 hours since I connected a 150 A/h to it. The battery had been half-pulsed before by another pulser over ten days, and I took it off to do some batteries I was contracted to fix by a 2nd hand car shop.

When I connected the battery I tested the SG and all cells were nearly at the green or exactly on. Well half a day later they are all at 1260 or perhaps a bit more.

The ten days of pulsing I did before was becoming tedious and towards the end it was difficult to see any further improvement. But a short time on a high-current pulse has finished the job.

My impression is that it worked like a dream. I mean this battery now is like a brand new one in terms of the SG and the plates look good.

I've run out of batteries which are sulphated, but I've got a few I did several months ago which I can try with this new machine.

I'll see if I can find a couple of dumped batteries tonight in the small hours outside battery shops (when no one's watching).

* I wasn't using the full power of this machine, but I would guess the amperage in the pulses I tried were approaching a hundred at the leading edge.

[mael]

[mael]

These days I am desulphating batteries until the SG is over 1260 in as little as a day, and most are done in three.

I've got six desulphators and I'm now in the process of rebuilding the earlier ones so as to incorporate the improvements I've noticed along the way.

I used six transistors on the output of a recently made pulser and it worked very well. I have made another using the same (90 A) transistors and that too is working very well.

I've even blown one set of transistors with a bit of inadvertant destructive testing. And as luck would have it it blew in the shorted position so it was lucky I was there to throw the power switch off. (But it wouldn't have blown had I not cranked it up so high).

Desulphating batteries by leaving them on a float charge for months at 13.1 - 13.3 V is one way. It works. I've tried three batteries on a long float charge and they wer all desulphated to the point they could be used without worry in your car.

Desulphating using a weak pulse of a few amps also works. If you are lucky it'll take a week for a small battery and a month or more with a small marine-type of A/h around 100.

But it is when you use tens of amps that things speed up remarkably. It doesn't seem to be the speed of the pulses so much as the current in them.

I prefer the larger machines which are capable of desulphating a battery in a day - three days as I'm trying to make a go of doing a business dealing with batteries I've rejuvenated/desulphated. - And on that score I'm not doing too badly. I've only got one company who wants my batteries, but I've sold them over twenty batteries of various sizes and they seem very pleased. It's saving them heaps of money. And all of my four bikes have batteries I've desulphated and they all crank the motor. And my wife's car, and her mother's car ... and a few friends have been given my batteries. Yeah! It works. No doubt about it.

So what's left to do? I'm planning to make at least two more desulphators using high current pulses. One is going to be fitted with a transistor block from an air-conditioner which is rated at 240 Amps. - Not that I'm planning to put 240 A through a battery, but as the power in the pulses can be adjusted by the base/gate voltage and by varying the pulse-width, any of the desulphators can handle a battery of any size.

I hope I shall be able to concentrate more on desulphating batteries and making observations. My having some more customers for my batteries would be the best way to allow this to happen. I'm not much of a salesman, but fortunately my wife is good at speaking to people and I feel confident when she is around - and so we'll visit a few places and see if we can't drum up some more business.

* I ought to be filled to the brim with confidence about what I'm doing and shout it from the rooftops. I mean I know it works! What's wrong with me? There's this doubting-Thomas floating around inside me and I can't shut him up.

I suppose this will be the last post in this thread as I've accomplished what I set out to do.

I hope to begin a new thread concerning what I observe occuring in the batteries I am treating.

But! I'd like to say I have just desulphated a Varta battery. It's 74 A/h, and it was a non-floater ie - water as electrolyte.

I had to access the cells to check/adjust the levels and to see the condition of the plates. - and what I saw apart from the sulphation were really nice solid and heavy/thick plates. I thought that it looked like a battery which would last for decades - and I'm sure it can. BUT! It's a sealed one. it was very difficult to remove the plastic cover and it's going to be a devil of a job to get it back on again without it leaking. I'll cross that bridge when I come to it - in the next couple of days or so. But the point of my mentioning this Varta battery was to say what a crying shame it is for such a well-made battery to end up as scrap for the simple reason it can not be maintained. I really hope people boycott those sealed batteries and encourage the manufacturers to sell ones with caps so you can maintain them.

Well......... Sleepy byes for now.

[redriderno22]