lead acid battery reconditioning

[hartiberlin]

Here are 2 more links to check out:

http://tech.groups.yahoo.com/group/batteryconversions/messages

http://www.greensaver.cn/en/product/productlist.aspx

[regbou]

Good afternoon!

I have been following this forum for some time and find some of the ideas interesting. I have been involved in battery reconditining for over 15 years. I have reconditioned ten of thousands of lead and acid batteries. Yes it can be done. Yes there are ways to get good results.
I have never tried Epson salts but have tried many other chemicals. The problem with those is that nobody wants to tell you exactly what those products are made of. A question of industrial secret apparently. One supplier simply told me that if he described his product in detail he would be out of business. I just can't cope with the idea that I would be using and working with products that I can't know anything about. What do you do if you or an employee is exposed to one of those products and finds himself in the hospital. If you can't tell the good doctor what he was exposed to, how can he be treated? It's a huge responsability that I refuse to take

What's more, there are very good and efficient alternative methods that give excellent results.

For those who are concerned about the possibility of explosions, I have had two such events in 15 years. It does not happen that often and as far as I know, it can only happen when you have a spark or flame, to ignite the hydogren gas that charging a battery produces. In a well ventilated area, this cannot happen as the gas is dispersed in the air causing no damage whatsoever. A battery casing can break open when being charged, if the vents are jammed or blocked. But it will not explode unless the gas is ignited. If the vents are functioning, the hydrogen gas will dissipate in the environment and unless the gas is in  large concentration and ignited, it cannot explode. Has anyone seen explosions caused in any other way?

regbou

[electricme]

@all

I discovered this last week, but my method only works if the lead bridges between cells are intact, and it also goes without saying the plates should also be intact.

Over the years I have used many methods to recover Gel cell batteries, but last week I tried something completly different to my usual way of charging a Gell Cell.

I had picked up a 12v Henry 12AH Gell Cell battery at the local scrap metal place in Town.

Getting it home I grabbed the DMM and it measured low voltage,
I put a 12v tail light globe accross the Pos and Neg, nothing happened.

I put the GC on charge, about 8volts, I let it sit there for hours.
Retest ,,,, nothing.

Next day I tried to charge it with 13.7volts for hours, again, nothing happened.

Next day, I tried abuse charging it, at up to 28V dc, for a couple of minutes, nothing, zilch.

Then I put 20ml of water in each cell,
I reconnect the charger, the battery began to accept a charge, but would not go any higher.

At the point of dispare, I boiled the billy, for a cupa tea, then I grabbed my big syerange and sucked up the hot water from the jug into it.

I squrted in each cell 50mls of boiling water.

WELL, This battery came to life instantly, I could actually see the voltage coming up, I connected the charger, it accepted a charge and in a couple of hours, it powered up my tail light globe to a nice white glow.

What's going on here?
Do you wash your hands with cold water or warm water or Hot water?
Soap helps, but I think the hot water partly dissolved the glazing on the plates, and when this occurred, everything went back to normal operation.

I have not tried adding additives to hot water, you all can do that ha ha.

Hope this can help you as it did for me.

hooroo

jim

[mael]

I have been working with used/old/discarded lead/acid batteries for about five years with the aim of making them work again.

At the moment I use homemade electronic desulphators built from scrap I find in the dumps at electrical stores.

I use varying amounts of power depending on the battery.   Size is the most important indicator of the amount of amps at each pulse it should receive in order to remove the hard sulphate crystals.  over 100 A at 50 milliseconds is nothing unusual.

After a year or so messing with various chemical and electrical methods to rejuvenate batteries I was able to get an '''average''' battery back to usable condition in a few weeks to a month. 

These days I can have a five year old car battery which sported electrolyte with a SG in the region of 1100 - 1150 ready in two or three days, and using ideas learned from each electronic pulser I've made I've got the desulphating down to 12 hours for a 40 A/h battery fairly reliably.

There is no doubt that electronic desulphating works, but I have tested one store-bought desulphator and found it was about as good as leaving some sulphated battery on a float charge - It was useless as far as I was concerned.

I've made nine or so electronic desulphators.  These days I use transistor blocks from old air-conditioner circuit boards for the pulse.  I drive them with a two-transistor astable multivibrator.  I've rebuilt a couple of them so I've got seven which I can use.

But I'm retiring at least one of them as it isn't much good compared to the newer ones I made which I improved by learning from it.

I'm going to make at least one more.  It's going to be the most powerful I've made.  The most powerful one I've got uses a transformer from a bench-top arc-welder and has about 30,000 mFds of caps being pulsed into 24 V at over a hundred amps (if I so choose).  It will go higher but at some point the transistor blocks are overloaded and they short -  But I sometimes test it on a couple of hundred amps before I turn it down.

That powerful charger is currently doing two 155 marine batts in series.  They've been pulsed for a week and the cells are now up to max level and the electrolyte measures within the green zone of my hydrometer.  (Used to take me at least a month to do batteries that size).

...  I've got a pair of Hitachi 210 marine batteries which I could 'do' with that charger, but I'm really itching to make that new one which will easily deliver a couple of hundred amps into those batteries.  I've got all the parts but I'd like some more caps.  i get my caps from air-conditioner pc boards as well and there are only three largish ones with each board.  Perhaps as summer is approaching I'll harvest a few dozen so I can get that big whack I just know does the job.

[mael]

I thought I should add this:-

Some of you might be shocked, but I use a relay to send the pulse to the gate of the output transistor modules.

I'm not that good with electronics and I'm skint so I have to make do with what I can salvage from old boards and adapt and abuse things so that they work the way I want them to. 

Anyway I can't think of anything else which will give me that virtually perfect pulse on the leading edge, and the relays I use are small and not under any appreciable strain and last at least two years at anything up to 40 pulses per sec.

If anyone is interested in following my philosophy of rejuvenating lead/acid batteries then you'll be of the mind that lots of small whacks with Amps achieves less than fewer much-stronger pulses.  In fact the pulsers I use will tend to charge as well as desulphate.

As I'm desulphating a battery I'll be watching for when the voltage seems to stabilise.  I like the voltage to be between 15.5 & 15.9 Volts.  That's just me.  Over 16 V and I think the cheaper brands of batteries might fall to bits.  (Like Panasonic).

If the V doesn't want to climb much over 14 V then there's a short of some kind ... the V ought to go over 15 V at least.

Anyway ... the circuit I use is literally a two transistor astable multivibrator which I feed into the base of a small power transistor and the relay coil is on a positive and the collector.

I adjust the timing by a few methods but I find that using a potentiometer on the resistor feeding the capacitors is very reliable and satisfactory.  One can get surprising speed from a relay by using an IC voltage regulator to get it to click just the right amount.  And I get millisecond(s) pulses by the aforementioned adjustment or by varying the base voltage into the relay-driving transistor.  ie... What I make certainly isn't state-of-the-art by any means.  But it works, and it works well.

I have experimented using solid state drivers but as I have mentioned I am not very good with electronics.  The astable multivibrators are fine for the job I need to do.